Restrictions on data-driven political micro- targeting in Germany

The revitalisation of canvassing in recent elections is strongly related to campaigns ́ growing possibilities for analysing voter data to gain knowledge about their constituents, identifying their most likely voters and serving up personalised messages through individual conversations. The research literature about political micro-targeting hardly ever focusses on campaigns in parliamentary democracies with strict data protection laws. Based on in-depth expert interviews we introduce a framework of constraints in strategic political communication and reveal several restrictions on the macro, meso and micro levels which hinder the implementation of sophisticated data strategies in Germany. We argue that political microtargeting highly depends on system-level contextual factors, budgetary and legal restraints, party structures and even individual decisions and knowledge on behalf of the campaign leadership.


INTRODUCTION
Despite the manifold opportunities presented by online campaign tools and multimedia channels nowadays, political parties in the US and Europe seem to have built a resurgent interest in an originally 'premodern' campaign tool to mobilise voters and ultimately generate votes: door-to-door canvassing.
This revitalisation heavily relates to campaigns´ growing possibilities for analysing voter data to gain knowledge about their constituents, identifying their most likely voters and serving up personalised messages through face-to-face conversations. A look at the extensive research literature about data-driven canvassing reveals a sharp contrast in the number of studies conducted in the US to research in European countries, and especially Germany. Therefore, the variation in the institutional frameworks, social and legislative conditions is almost limited to the one-country case and reveals the existence of a research gap regarding data-driven canvassing in parliamentary democracies with strict data protection laws.
This said, the Obama, Clinton and Trump campaigns made data-driven campaigning and micro-targeting known to a broader public. In Germany, data-driven efforts are a subject of controversial public discussion: critics fear manipulations of voters and violations of national privacy laws. On the opposite, supporters hope for a mobilisation of specific target-groups like swing voters or infrequently voting partisans who often abstain from voting.
Based on theoretical predictions derived from the extensively studied US case, we discuss datadriven political micro-targeting against the backdrop of canvassing in the German social, legal and electoral context from a political actor´s perspective. Three central research questions structure our work: (1) What importance do German parties attribute to the use of data for targeting voters in contemporary campaigns? (2) How do German parties use data for targeting voters through canvassing efforts? and (3) What are the restrictions on data-driven political micro-targeting in Germany?
In a first step, we discuss the theoretical, historical and legal principles of data-driven canvassing with a comprehensive review of literature on data-driven campaigning and data protection laws in Germany. Drawing on that discussion, we introduce a framework of constraints in strategic political communication and address our research questions with findings from an analysis of in-depth expert interviews with nine campaign coordinators of parties running in the state parliament of Rhineland-Palatinate in 2016 (Christian Democrats 2016;Nielsen, 2012). Besides broader discussions about modes of professional campaigning in Europe (Tenscher, Mykkänen, & Moring, 2012) the literature on the role of data and technology for political parties in countries with strict national privacy laws has not been systematically reviewed yet. Therefore, we present a literature review of data-driven campaigning in Germany with a special focus on canvassing. In this process, we highlight and define crucial terms, give insights into the emergence of modern campaigns´ communication channels and the influence of data.

DATA AND MICRO-TARGETING IN POLITICAL CAMPAIGNING
In the context of political communication, we understand micro-targeting as a strategic process, which is geared towards addressing persuadable or mobilisable voters with tailor-made messages while ignoring others. Castleman (2016) distinguishes two terms that are often used interchangeably: "modeling" and "micro-targeting".
Modeling describes the practice of using algorithms and observed data to build statistical or machine learning models to mine users with similar attitudes and behaviours (clustering) or predict unobserved actions or preferences (predictive modeling). For political campaign communication, models are often built at the individual level using survey data or relevant voter information. On the one hand, compiled information by local and state election authorities (e.g., voter files, structural data sets) contain voters´ addresses, sociodemographic characteristics, voter turnout records or voting histories for specific districts or states. On the other hand, more individual (behavioural) information from a campaign´s own data or from commercial data vendors include donation activity, campaign contact histories, consumer records or digital trace data.
Micro-targeting is a commercial direct marketing practice and refers to the process of making strategic decisions at the individual level about which customer to target with what campaign message (see also the Editorial of the special issue). In sophisticated campaigns, algorithmbased models inform these decisions. Therefore, modeling and micro-targeting are clearly linked, but they are not inseparable as modeling can still be done on other types of data, and micro-targeting can be done in the absence of models. Therefore, different approaches of political targeting can be distinguished: geographical targeting is the oldest --and most coarse --approach. It is based on the analysis of precinct-level results from past elections to identify auspicious electoral constituencies. Another approach is targeting groups with shared demographic characteristics such as income, religion or occupation. Reliable data about a series of demographics is needed to build algorithmic models for distinguishing individuals for each targeted voter group. Sophisticated targeting-approaches are based on the analysis of individual attitudes, behaviour and values of the electorate. Building on the assumption that these characteristics are more coherent with the voting decision, they promise satisfactory

IMPLEMENTING DATA INTO GERMAN CAMPAIGNING
Although the roots of data-driven campaigning in Germany can be dated back to the times when public opinion polls were on the rise in the early 1950s (Noelle-Neumann, 1955) tentative attempts with more sophisticated practices took place in the context of the federal election 2005 with grassroots campaigns from CDU ("teAM Zukunft"), SPD ("wirkaempfen.de") and the Greens ("Mach Mit!") (Jucknat & Römmele, 2008). These campaigns were carried out "completely isolated from other campaign activities" (Hennewig, 2013, p. 160) in distinct constituencies and lacked a "proper communication and entrenchment in the main campaign organisation" (Heinrich, 2013, p. 176). As a result, only widely scattered campaign aides and party sympathisers were reached and could not be used as strategic communication multipliers.
As a result of the attempt to import campaign practices from the US-election cycle 2008, various improvements were made in the German federal election 2009: both CDU and SPD connected their organisation platforms (CDU: teAM2009.de; SPD: meineSPD.net) with databases to build up a central organisation structure and implement the grassroots activities into the main campaign.
However, the platforms´ level of interactivity, dynamic and participation clearly lagged comparable platforms like Barack Obama´s MyBO in 2008 (Lilleker & Jackson, 2011), resulting in a more or less ineffective mobilisation of volunteers throughout Germany. In addition, first attempts were made at targeting potential voters within demographic groups or mobilise sympathisers in geographical regions using so called 'mobilisation indices'. Nevertheless, voters were only marginally aware of target specific communication channels: only two percent of voters were conscious of email, social media or SMS contacts while a majority was aware of posters (75%) or TV ads (50%) (Schmitt- Beck & Wolsing, 2009, p. 51). In that regard, German campaign strategists started to understand the problems and complexity of implementing these new campaign practices and technologies from one national, legal and party context to another.
Although German parties began to experiment with more sophisticated data analysis and technologies in the federal election 2013, they still struggled with staff, time, expertise, money and strict data protection regulations to establish a high-tech driven hunt for individual voters.
As a result, the German targeting efforts were more of an exploration in the dark instead of a target-oriented campaigning strategy.
These developments go hand-in-hand with social, political and technological changes, which ultimately result in a political actor´s need for an enhancement of electoral communication strategies mostly described as "professionalization" or "modernization" (see Kamps, 2000). The evolution of data-driven campaigning can best be described along the adapted model of ideal campaign types by Magin, Podschuweit, Haßler, & Rußmann (2017) (see Table 1). It focuses on four ideal campaign types, which emerged within a certain time frame when the essential technological possibilities became available: 1) Partisan-centered campaigns address the core party members and partisans with face-to-face interactions, partisan press, newspaper ads, radio broadcasts and posters. Thus, campaigning was rather based on local and decentralised strategies. 2) With the establishment of nonpartisan media and limited-channel television, the range of mass media coverage expanded radically. Mass-centered campaigns emerged and provided the opportunity to address disperse masses by unidirectional messages while also being supplemented by partisan-centered campaigning

MAKING USE OF DATA IN GERMAN CAMPAIGNING, DRAWING ON THE EXAMPLE OF CANVASSING 2.0
We showed that improved capability to target individual voters offers campaigns an opportunity to concentrate their resources where they will be most effective. As Nickerson and Rodgers (2014, p. 71) put it, "[o]ne could argue that the growing impact of data analytics in campaigns has amplified the importance of traditional campaign work". Thus, door-to-door canvassing is currently experiencing a renaissance among parties and election campaign strategists in diverse political systems. It was primarily during the 2004 presidential elections that data-driven canvassing emerged as one of the key instruments in the Howard Dean and George W. Bush campaigns (Kreiss, 2016) and sparked worldwide attention as decisive factor behind Barack Obama´s successful presidential bids in 2008 and 2012 (Nielsen, 2012;Kreiss, 2012;. However, canvassing is by no means an invention of modern election campaigns. On the contrary, it dates back to the rise of contested elections in the UK and was also used by the National Socialist Workers' Party (NSDAP) during the rise of Nazi-Germany (Mühlberger, 2004). After World War II, canvassing was almost suspended until the 1960s, when German parties started using it in local elections and switched their canvassing strategies away from persuading eligible voters to identifying sympathisers or supporters and mobilising them. While television became increasingly popular since the early 1950s, parties shifted their resources from the 'ground game' to mass market advertising, with canvassing seen as "relics of the past" (Beck & Heidemann, 2014, p. 268) and an elaborate ritual bringing gratification to campaign aides and supporters, but making no difference to election results (Denver & Hands, 2013).
However, with declining electoral turnout, an increasing diversification of electronic media and the corresponding fragmentation of media use among the electorate, the generic mass media´s one-way scattergun approach of campaigning became increasingly unsuccessful in reaching, let alone mobilising or persuading specific target-groups. Therefore, door-to-door campaigning attracts attention from campaign strategists. It allows for unique contacts that stand out from the media torrent, reaches a clearly defined universe of individual targets, and has measurable effects (see, among others, Green & Gerber, 2008;Michelson & Nickerson, 2011).
After Barack Obama´s re-election campaign in 2012 was lauded for its sophistication in ground organisation, data analysis and micro-targeting, German parties tried to find ways to translate door-to-door canvassing into the German electoral setting. First attempts with data-driven canvassing were made at the federal election 2013. The aim of these canvassing campaigns was to reach out to the voters, get votes from the undecided and draw those back to the party who defected in the last election (2009). The sentiment of going to the people instead of them coming to the party is a big shift in German campaign philosophy. German voters are used to only entering in contact with party members at a rally or stop by a party information booth in public areas. A representative survey by YouGov (2017) also reflects this sentiment and shows that a majority of Germans (65%) are still uneasy about opening their door to a political party.

A FRAMEWORK OF CONSTRAINTS IN STRATEGIC POLITICAL COMMUNICATION
Against the backdrop that certain social, political, legal, technical and cultural contexts underlie strategic political communication, we adapted the analytical framework by Vowe and Wolling (2000) to explain constraints related to decision making in campaign communication in different contexts. A key statement condenses the underpinning theory into one sentence: "Every strategist risks the success of his venture if he neglects the conditions which determine his actions." (p. 58) Drawing on this, we argue that there are three constraint dimensions for the strategic use of certain campaigning strategies and tools: 1) external dimensions (Macro level), 2) internalorganisational dimensions (Meso level) and 3) individual dimensions (Micro level) (see Table   2). The model is suitable either to explain a particular case, for example a campaign in one country, or to compare campaign cases in different nations. In this paper, we present empirical findings of data-driven canvassing in Germany and therefore use this framework and its leading categories for interpreting data collection and presentation. In the following, we present each dimension along specific subdimensions:

1) MACRO LEVEL OF CONSTRAINTS
1a) Electoral and party system: Generally, presidential government systems offer more incentives for strategies of individual-centered-campaigns than parliamentary systems, which are characterised by party-focused styles of campaigning. This is especially the case for the German electoral system, where two votes are casted: one for a direct candidate (determines by plurality vote who will represent each constituency in the parliament) and one for a party list (determines the distribution of seats in the parliament). In Germany´s multi-party system, parties don't enjoy much flexibility in addressing (non-affiliated) voters because they need to put distance between themselves and their opponents with distinct ideological profiles and issue agendas. This doesn't suit the logic of individual-centered-campaigns very well. Furthermore, countries with high levels of party identification and high numbers of enrolled party members can potentially rely on stronger support for party-driven campaign operations. Thus, Germany´s tradition-rich 'programmatic parties' are relatively deeply rooted within society and are not so dependent on targeted practices. Lastly, German parties are mostly financed by membership fees and state funds which derive from the outcomes of the elections (statistics can be found at Deutscher Bundestag, 2017). Although donations by private persons and organisations are also allowed, they are much lower than in the US.
1b) Political culture: Germany can rely on comparatively high turnout cultures and constituents with political beliefs that are intact. However, recent studies observed a general process of partisan de-alignment also in Germany (Dalton, 2004), meaning fewer people have fixed attachments to political parties and fewer are now members of the same. This leads to a decline in voter turnout and an increased electoral volatility and makes elements of individual- collection (data avoidance) and regard data economy ( §3a BDSG). The collection of data is only allowed to fulfill a specific purpose ( §28 (1) BDSG). Political parties can gather data if they are necessary for their organisational activities. However, this is limited to the personal data of party members or persons who have regular contact to the organisation ( §28 (9) BDSG).
Furthermore, data can only be collected when affected persons explicitly agree ( §4a BDSG).
People also have the right to have their data rectified, cancelled and blocked ( §6 (1) BDSG). In contrast to the US, where political databases are updated regularly, the German law forbids a storage of personal data for the long-term. Data has to be deleted when the purpose is fulfilled ( §35 (1) BDSG). In addition to that, political parties are not allowed to store data on racial or ethnic origin and political, religious or philosophical beliefs ( §35 (2) BDSG). This leads to the problem that German campaigners cannot build larger databases for micro-targeting. Lastly, German data protection is integrated into a larger legal framework: the EU Charter of Fundamental Rights (Article 8).

2) MESO LEVEL OF CONSTRAINTS
2a) Party culture: German parties differ highly in their organisational structure or culture. The SPD is an example for a highly democratic internal organisation structure which also extends to its processes (Langenbacher & Conradt, 2017, p. 140ff.). More than 12,000 local associations (Ortsvereine) make up the core of it. These are grouped together into sub-district, district, state and youth organisations. The subdivisions determine SPD´s policy and elect their party leader and the members of several committees, like the Executive Committee, which in turn elects SPD's 13-member Steering Committee (Präsidium). This democratic structure is vertically and horizontally intertwined, making the SPD a highly democratic but also slow working apparatus.
This can pose a problem in time of elections, in which fast and sometimes disagreeable or policy dissenting decisions must be taken. As the archetypal pragmatic and office-seeking 'catch-all party', the CDU is an example for a decentralized party organisation structure (Langenbacher & Conradt, 2017, p. 148ff.).  (Maarek, 2011).
Politicians can be another constraining factor. As personifications of party ideologies, they are in the centre of the campaign organisation and have the power to decide over every aspect in a campaign. If politicians refuse to use data-driven tools, the whole campaign organisation is affected by that decision. Studies about data and technologies in German campaigning are scarce, so we firstly wanted to know what the involved German campaign strategists think about the role of data for their campaigns. We expected a high interest in these strategies from all parties, but depending on the individual expertise and experience, the attributed importance may vary.
2) How do German parties use data for targeting voters through canvassing efforts?
We secondly wanted to gather more detailed insights about the state of data-driven targeting strategies in contemporary German campaigns. Here, the type of used data, its analysis and strategic implementation into the campaign communication is of special interest. In the light of the party system, party funding and party culture variations between German parties may occur.
3) What are the restrictions on data-driven political micro-targeting in Germany?
Drawing on the assumption that political campaigns are shaped by its conditions and contexts we expect restrictions on the macro, meso and micro level that hinder the implementation of sophisticated data-driven micro-targeting strategies in contemporary German campaigns.
Our study will gives important first insights into the state of data-driven campaigning in Germany as parliamentary democracy with strict data protection laws. Therefore, our case might be useful for generating comparative theory and hypotheses beyond the scholarly knowledge of these strategies in the US context.

METHODOLOGY
Research on political campaigning means difficult access to the field in most cases. During and before political campaigns, campaign officials and staffers try to hide their strategies from the contestants and public (Jungherr, 2017). Besides experimental approaches to quantify the effects of certain communication efforts (see, among others, Green & Gerber, 2008;Michelson & Nickerson, 2011), studies on political campaigning either use theoretical or qualitative approaches (Jungherr, 2016;Nielsen, 2012). However, the studies of Jungherr (2016) and Nielsen (2012) (Drummond, 1967, p. 385). However, there are some differences between German first order (federal election) and second order elections (federal state elections): 1) In German second order elections voter turnout is lower, and the willingness to punish the established parties greater than in the case of general elections (Bräuninger & Debus, 2011).
This leads to a greater likelihood of new and extreme parties being given the vote, which at the same time means that mainstream parties, and especially ruling parties, must make greater effort to inspire their regular voters to go to the polls -in other words, to mobilise them.
2) Apart from that, local in comparison to federal elections are characterised by the fact that parties even have more limited electoral budgets at their disposal (Lewandowsky, 2013 In order to gain access to the largely unexplored phenomenon of data-driven canvassing in Germany, our study is also qualitatively oriented and uses six in-depth expert interviews with nine campaign coordinators of the most promising parties running for state parliament of

EMPIRICAL FINDINGS
To answer the leading questions about the importance, use and restrictions for micro-targeting and canvassing in Germany, we will present our findings along the framework of constraints on the macro, meso and micro levels.

1) MACRO LEVEL: SYSTEMIC RESTRICTIONS
1a) Electoral and party system; 1b) Political culture All German campaign managers agreed that data-driven campaigning has arisen during an era of partisan de-alignment and declining vote share. Therefore, parties "must find newer methods to engage with the electorate in a more complex, multiparty system" (SPD). Contrary to the US or the UK electoral system, which incentivise parties to use their resources to target voters in battleground states, the German electoral system is characterised by proportional representation, long-established party strongholds and rare competitive constituencies.
Therefore, German campaigns need other data sources to decide which constituencies should be targeted by canvassing efforts. The Green campaign managers mention an "urban-rural-gap" which gives their Party advantages in cities, particularly those with universities. The other experts say that party associations also reflect economic divides (The Left), and that some parties tend to fare better in one region or the other because of "historic ties" (CDU) to the area or "persistent socio-economic differences between them" (SPD). Another finding is that new and smaller parties do not have good chances because the political landscape is more oriented towards the bigger parties due to stable electorate milieus. The right-wing party manager additionally mentions social marginalisation of the party because of its controversial standpoints (AfD).
In the German parliamentary system, campaigns must also decide if the canvassing campaign should get the first or second vote. This affects if a candidate has to join the canvassers at the doorsteps (The Left, CDU) and how to talk to the voters at the door. Taken together, the German political culture, electoral and party system makes the organisation of data-driven canvassing campaigns especially challenging. Because German parties lack other data sources and more detailed information, they use geographical targeting and focus on "constituencies that had been party strongholds in the past, but saw lower voter turnout in former elections" (CDU, SPD, The Greens).

1c) Legal concerns
All campaign managers show a great caution with regards to data protection standards in Germany. Exemplarily, the SPD manager says "Data is a highly sensitive topic. There are literally millions of data providers on the market and it was clear to us that only somebody serious is eligible for us." The interviewee also named a main reason for that, namely that the party must be trustworthy and transparent because there is great distrust among the public about persuasive political campaigning techniques. This also applies to targeting technologies which differ noticeably from US techniques which, according to the Left campaign manager, "could never migrate to Europe because the sensitivity of data concerning political affiliation is rooted in a German political culture". Therefore, "the smallest target units are streets and constituencies not households" (SPD). Although, all parties attribute a high importance of data for their campaigns, only some have experimented with different data sources to find the ideal way for the strategic organisation (SPD, CDU). Because of that, the SPD manager stresses the importance of focusing on a few constituencies with high potentials and low wastage of advertising. To 'circumvent' the strict data laws, German parties started to collect data with apps (CDU) or clipboards (SPD) at the voters' doorsteps, which are computerised in a database. In terms of law-abidance, this also needs explicit declarations of consent which is not possible on a large scale. Additionally, data must not be stored over longer periods. This consequently means that German data laws impedes micro-targeting based on the US model.
Nonetheless, high standards in European data protection laws do not ultimately prevent the implementation of micro-targeting. Bennett (2016) reminds that the term "political opinions" in the European General Data Protection Regulation is not clearly defined. Thus, these data could be allowed to be processed if political players can prove that the targeted person is in regular contact with the party. Besides, Bennett adds further external forces putting pressure on European legislation: a shrinking core voter base which leads to more market-oriented campaign strategies. These define voters as customers who need to be contacted with the use of targeting methods. Furthermore, technological (read marketing companies) and social forces could influence the future design of data protection laws in Europe.

2a) Party culture
Drawing on the interviews, party cultures within political parties played a significant role in shaping their use of data and canvassing efforts. Members of party divisions with a long history tend to be very self-confident and often refuse to follow the headquarters' rules for canvassing (SPD). So, the campaign managers are only able to declare focal points for canvassing but "cannot instruct the local chairman to do canvassing in a particular area." (SPD). "Nevertheless I don't want such a structure like in the US, as the German thing with traditional local committees is fantastic." (SPD). Contrary to US campaigns, where campaign assemblages (Nielsen, 2012) get together before elections, German parties are working throughout the year. This means local party committees are additionally planning and carrying out campaign measures (SPD, FDP, The Left) which is useful for the campaign headquarters as they are "dependent on the local structures" (SPD) to save resources and to carry out the exhaustive campaign. According to the interviews, German party culture is characterised by top-down as well as bottom-up communication which can be used to produce a better understanding of new campaign strategies (CDU, SPD, FDP, The Left). Especially the Green Party tries to empower its members to become a part of the opinion-forming process and the planning of the campaign.
Furthermore, the Green's party ideology limits the use of data in campaigns because it's a "question of faith" whether the party should purchase information on voters. Still, they commission the Deutsche Post for direct marketing efforts.

2b) Personnel and financial resources
Generally, the campaign experts stated that the campaign funding is based on their local savings without any financial help of the national party. The logic behind this system assumes an institutional separation between the two. Unlike PR methods and the use of social media, data canvassing is a highly resource-intensive instrument. As we have mentioned above, German parties have limited budgets at their disposal and have to "make a smart mixture" (SPD) of possible communication channels limited by a tense budget situation. Although there are attempts to send out paid staff, financial restrictions are a key constraint: "We cannot afford to pay everybody at any place for canvassing." (SPD) Missing money also affects feedback from voluntary canvassers, as they do not have the obligation to report to campaign headquarters (SPD). In addition to that, investments to external consultants (FDP, SPD), data vendors (FDP, The Greens) and the purchase of data (SPD) are further positions in the budget. Particularly the data service by German Post Direct is "really expensive" (FDP).
Especially smaller parties struggle with financial constraints, which could consolidate power in the larger and better financed parties and make it more difficult for smaller parties to be nationally competitive. Therefore, concerning the organisation of campaigns, managers of the AfD and The Left "listen to their gut feeling".

2c) Technology and infrastructure
Contrary to US campaigns, digital tools are not fully established in German federal and state elections. However, the interviews with the CDU, SPD and The Greens revealed attempts to professionalise campaign infrastructures in Rhineland-Palatinate: the SPD tried to mobilise volunteers by using a digital platform where party members can connect and stay up-to-date.
This site can also be used to coordinate canvassing operations. However, SPD's campaign managers did not see great benefits because the platform lacks usability, more detailed information about constituencies or streets and possibilities to interact. The SPD managers even put more emphasis on analogue channels of internal communication: "We are using stuff which suits our members best... and that is paper. I think we had most information in a final document, brought it to the trainings and distributed it in our offices" (SPD). This finding is also

3b) Volunteers & party members
Members are described as "the centrepiece" (SPD), "the backbone of the campaign" (The Green Party) and as "very engaged" (AfD). However, party members and sympathisers are not professional and paid agents using elaborate techniques in their campaign activities, although there are attempts to integrate low-paid persons (SPD). Therefore, the major challenge is to mobilise and manage party activists to engage in the campaign. People must be convinced(The Greens, SPD) of the campaign before they get involved: "I think the great age of party soldiers is over except for a few cases. You have to grip people and they have to be keen on campaigning."  (CDU) In summary: "It is not easy to mobilise people." (SPD)

DISCUSSION AND CONCLUSION
We showed that German local campaigns make different attempts at targeting voters with direct contact at their doorsteps based on data analysis (see Table 3). Past election results and turnout ---------

Data collection
Paper and Pencil --------------- Although all German parties show wide interest in the use of data and canvassing for voter targeting, only the two main parties (Volksparteien -CDU, SPD) see them as important to their actual campaigns. As a result, they invest time, money, know-how and staff. However, our findings show that German 'data-driven' canvassing cannot be compared with the highly sophisticated US campaigns which use reliable data, experimental findings and data modeling to identify individual voter targets like swing voters or infrequently voting partisans -"many of whom pay little attention to news and who frequently are not interested in (or even decidedly disenchanted with) electoral politics" (Nielsen, 2012, p. 18). In contrast, German parties use geographical targeting based on the analysis of precinct-level results from past elections to identify auspicious electoral constituencies for their canvassing efforts. According to Nickerson and Rogers (2014, p. 51f.) these techniques were used "as recently as a decade or two ago […] and appear extremely rudimentary by current standards". Although this study is limited because it focuses on a single case state legislature election, it provides important insights for further discussion and generating hypotheses on a comparative and normative level. Our results show that certain factors on the macro, meso and micro levels hamper the strategic and sophisticated use of data-driven canvassing. Moreover, the relationship between data-driven targeting and electoral, legal or individual context factors seem important for its usage, raising the follow-up question: which contexts are most fruitful for these strategies? Furthermore, parties are eagerly interested in the implementation of individual-based campaigning techniques without thinking about implications for personal privacy, civil liberties and democratic values. Concerning personal privacy, legal regulations can be re-considered and adjusted by governments if personal data is not protected against data collectors. More fundamental changes could arise in the democratic discourse: since data-driven campaigning aims at "useful" voters, less "important" voters are excluded from the campaigns (Hillygus & Shields, 2008). Consequently, political topics of these voter groups could be neglected in the political discourse. In a worst case scenario this could lead to a defect in democratic discourse when specific minority issues are not even addressed by politicians for strategic reasons. Additionally, targeted voters are confronted with selected information on certain topics (Nielsen, 2012) which can be assessed as manipulative communication. Taking research on instant influences into advance, repeated and partisan information stimuli could have an impact on the attitude and behaviour of voters (Papakyriakopoulos, Shahrezaye, Thieltges, Medina Serrano & Hegelich, 2017). Bennett's (2016) claim that developments in other nations, particularly the US, combined with external forces from the technology sector and the economy could lead to an increasing demand of data-driven methods in Europe has to be taken into account. Consequently, political