While voters in elections have attracted considerable scholarly scrutiny over the past half century or so, studies of campaign donors are less abundant. There are many good reasons for this lacuna, starting with the fact that donating to campaigns is generally much less commonplace than voting. There are also data limitations, and many donor studies rely on self-reported behavior that may be inflated or unreliable. Further, many survey items do not probe respondents to detail the amounts or specific recipients of their contributions. There are also structural barriers, including the fact that federal campaign finance law does not require campaigns to disclose the identities of donors who contribute less than $200 to candidates (small donors), and so researchers are often in the dark about these donors. As a result, much less is known about donors than voters in American elections.

In large part thanks to David B. Magleby, Jay Goodliffe, and Joseph A. Olsen, this gap is shrinking. In Who Donates in Campaigns? the authors marshal an impressive amount of empirical evidence to shed light on the characteristics, motivations, attitudes, and behaviors of donors in recent presidential elections. In doing so, they provide a useful update to previous studies of campaign donors, but they also extend the literature on campaign contributors in very significant ways. For example, their data facilitate comparisons with previous election cycles, as well as between small (unitemized) and large (itemized) donors. Their panel data also permit explorations of the same donors across election cycles. Meticulously researched and masterfully analyzed, the book overall represents a significant contribution and the most up-to-date and comprehensive treatment of campaign contributors in recent elections.

By far, the most impressive feature of the study is the access to actual donor records provided by the presidential nominees’ campaigns in 2008 (Barack Obama and John McCain) and 2012 (Obama and Mitt Romney). Because top contenders in contemporary presidential elections generally opt out of the public funding program that would require them to disclose the identities of small donors to the Federal Election Commission (for matching purposes during primary campaigns), the only way to secure such information for research purposes is with the consent of the campaigns. Remarkably, Magleby, Goodliffe, and Olsen persuaded the presidential nominees in these two cycles to provide them with random samples of small donors that, when combined with publicly available itemized donor records, allow the researchers to compile samples of all donors to the major-party presidential nominees in both cycles.

The fact that these cycles were crucial and historic from a campaign finance perspective (Obama, in 2008, and then both major-party nominees in 2012 rejected public funding in the general elections for the first time since the creation of the presidential public funding system in 1976) is all the more astounding. The ability to survey donors at all giving levels over two election cycles enables the authors to compare small and large donors using separate cross-sectional stratified random samples. As the authors note, “[n]o prior donor study has had access to this particular data resource” (p. 25). Another commendable feature of the study is the panel component in which 2008 donors were reinterviewed in 2012. This design feature is unique, and it enables the authors to track individual behavior and attitudes over time (p. 25). The authors also leverage data from the Cooperative Congressional Election Studies, as well as individual-level information about donors procured from Catalist, a commercial research company that maintains an extensive national database of voter information.

These elements alone would make this the definitive study of contemporary campaign donors, but the authors do not stop there. They supplement their original data-collection enterprise and rigorous quantitative analyses with rich, qualitative details culled from hundreds of interviews with top campaign officials, operatives, and experts whose views and reactions help to contextualize and otherwise situate and interpret the empirical evidence. This combination represents a monumental scholarly achievement and a model for social scientific excellence.

Along the way, readers get an unprecedented glimpse into contemporary campaign donors, as well as their attitudes and behaviors. We learn, for example, about the demographic composition of donors in 2008 and 2012 and how this compares to previous cycles. The donor profile for Republican presidential nominees has remained remarkably stable relative to previous cycles—overwhelmingly white, older, well educated, affluent, and male—while Democratic (Obama) donors were less affluent, younger, and more likely to be African American. Democratic donors were also more balanced with respect to gender and education levels, although a central observation is the surge in Democratic female donors in 2008 (which persisted in 2012).

The authors also find that there have been more Democratic than Republican presidential donors since 2004, in sharp contrast to the partisan composition of donors between 1972 and 2004. In Chapter 6, they observe that small donors in 2008 and 2012 were as ideologically polarized as itemized donors, and that Romney itemized donors in 2012 were more ideologically extreme than Obama itemized donors (p.192). On issues, the analyses reveal few differences between itemized and small donors, after controlling for demographic and attitudinal characteristics, except among Obama small donors in 2008, who supported same-sex marriage more than itemized donors did (this difference vanished in 2012).

The authors’ analyses of donor motivations provides important insights. While prior studies have found that donors are motivated for material, solidary, and purposive reasons, the current research finds that only purposive motivations endure. Solidary or material motives do not appear to drive contributing behavior, as the literature has long claimed (p. 12). The authors link purposive motives to a candidate’s message (including issue positions) and assert, on the basis of contrasts in their findings to studies of voting behavior, that the “[m]essage appears to be even more important to donors than it is to voters” (p. 13). The authors also emphasize the importance of the messenger, medium, and structure, considerations that have “not been given much, if any, attention in previous studies” (p. 12). “Messenger” refers to a candidate’s appeal, “medium” focuses on the impact of the Internet and new media in fund-raising and organizing (these developments helped to fuel a surge in small donors, in particular, over the period of their study), and “structure” refers to changes in the legal and regulatory landscape that influence donors and campaigns (for example, changes to individual and aggregate contribution limits or the landmark U.S. Supreme Court decision in Citizens United v. FEC that dismantled independent expenditure prohibitions for corporations and labor unions and led to the formation of Super-PACs). This framework reflects an important theoretical contribution that will likely shape subsequent inquiry in this domain.

The panel study analyses, reported mainly in Chapter 5, investigate changes over time. These novel data allow the authors to zoom in on “lapsed” (those who gave in 2008 but not in 2012) as well as repeat donors. These analyses reveal, for instance, that the messenger matters more to new donors, while the message is more important to repeat donors (p. 27). The data also show that more than a quarter of Obama’s 2008 donors failed to contribute to him in 2012 (mostly because they reported “having less money”), but that Obama was able to replace lapsed 2008 donors with new donors in 2012. They also discovered that lapsed donors were younger, less affluent, more likely to be male, less partisan, and less interested in campaigns than continuing donors (p. 28). This is the first study of its kind that can shed light on these important questions.

In Chapters 8 and 9, the authors extend their study to explore the timing of campaign contributions and the policy implications of changing laws and regulations, respectively. They link campaign events and other key developments to patterns of contributing behavior, finding that Federal Election Commission reporting deadlines, organizational strength, and campaign events, like McCain’s selection of former Alaska Governor Sarah Palin as his vice-presidential running mate, can affect campaign fund-raising. The authors also reflect on the likely effects of policy interventions designed to encourage contributions, including matching programs, tax credits, or deductions and vouchers, concluding that these “would likely increase the number and diversity of donors” (p. 324). They also weigh in on disclosure requirements and “independent electioneering.” Throughout the book, Magleby, Goodliffe, and Olsen also offer some reflections on the 2016 election cycle, speculate about its implications, and conjecture about subsequent election cycles.

Overall, the arguments and evidence presented in this book provide readers with a convincing and comprehensive overview of change and continuity in contributing behavior in federal elections over the past several decades, and especially in 2008 and 2012. The study is impressive, although, like any study, it is not without limitations. For example, the focus is almost exclusively on federal campaign donors, and especially on presidential donors; donors to state and local campaigns are excluded. In addition, comparisons with previous studies often overlook key differences in donor samples. Finally, as I noted earlier, the 2008 and 2012 donor samples are commendable and unique, but they are also incomplete. They exclude, for instance, small donors to Hillary Clinton’s campaign in 2008, which raised nearly $200 million from individual donors (including over $40 million from small donors) in that primary election cycle. It is unclear how many of these donors gave to Obama in 2008, thereby potentially capturing them for the current analyses, or subsequently lapsed or returned in 2012. On the Republican side, McCain’s sample of small donors was presumably restricted to the primary campaign since he opted into the public funding program in the general election, prohibiting his campaign from soliciting private contributions at that stage. By contrast, the 2012 Romney small-donor sample blends primary as well as general election contributors. These limitations notwithstanding, they do not diminish the book’s extraordinary strengths.

Looking forward, this line of inquiry can be extended further in interesting ways. The data can be exploited to explain individual contribution amounts, for example, and to explore more explicitly the full range of contribution levels; it is plausible, for instance, that small donors who gave $5 could differ in meaningful ways from small donors who gave $150; similarly, a $250 donor could be quite different from one who maxed out or gave $2,000. Given the paucity of this kind of data, such analyses could shed light on several additional and compelling questions. In the meantime, however, readers who wish to learn as much as possible about contemporary campaign donors in a single shot should start with Who Donates in Campaigns?