Donate To Help Us Fight Back: Mobilization Rhetoric in Political Fundraising

Political candidates utilize social media to mobilize supporters, persuade voters, and raise money. However, little is known about the structure of mass electoral appeals when donors are the primary target instead of voters. Because candidates' donors and voters can differ significantly, with donors more partisan and ideologically extreme on average, we theorize that candidates use strategic rhetoric tailored to specific audiences. To analyze how campaigns perceive and target their "financial electorate,'' we leverage data from the Facebook Ad Library for 2020 U.S. congressional candidates and distinguish political ads by their persuasion targets. Using text analysis, we test the hypotheses that donor-targeting messages are more toxic, negative, and likely to reference a polarizing president than voter-targeting messages. The results support our hypotheses, and Republican candidates, on average, used more toxic language than their Democratic counterparts. As campaigns' scramble for donations intensifies, these characteristics of fundraising appeals may further polarize the electorate.