Keep Winning with WinRed? Online Fundraising Platform as the Party's Public Good

What determines the relative importance of extended party networks versus party leaders in parties' campaign strategies? We synthesize theories of party organizations by highlighting the interplay between formal institutions and extended networks, using an example from U.S. campaign finance. Online platforms are increasingly important in political fundraising, and party-wide platform coordination increases efficiency for any party. However, parties' strategies sharply diverged: ActBlue for Democrats was created outside of and run independent of the party leadership, while WinRed for Republicans was created and controlled by party elites. We argue that asymmetries in the composition and incentives of extended party network members allowed ActBlue to grow organically but hindered natural coordination for Republicans. Analyses of platform communications and solicitation strategies show that, indeed, only the GOP actively intervened in members' platform choices to overcome coordination failures. Matched-panel analysis proves the strategy effective; Republican candidates reaped sizable fundraising rewards from joining WinRed.