The quantity of "horse-race" coverage of political campaigns has been amply documented, but its consequences for the dynamics of campaigns are less well understood. This study examines the effects of media portrayals of public support for candidates on the behavior of potential campaign contributors. This relationship is tested in the context of the four leading Democratic presidential primary candidates in 1988. A time-series analysis of contributor behavior suggests that horse-race spin—that is, the extent of media coverage suggesting a candidate is gaining or losing political support ^helps determine the frequency of campaign contributions. Consistent with previous research, some contributors are motivated to donate by coverage suggesting that their strongly favored candidate is losing ground, while other candidacies benefit from coverage suggesting increased viability. Overall, findings suggest that strategic considerations weigh heavily in decisions to donate money to political candidates.