Substantial academic interest and public policy debate centers on campaign finance reform. Campaign resources can provide benefits to constituencies if candidates use them to fund the distribution of useful information. On the other hand, voters can potentially be harmed if candidates trade policy favors to special interests in exchange for contributions. Unfortunately, because informative field data on this topic are very difficult to obtain, the effects of different campaign finance strategies on election outcomes and economic welfare remain largely uninformed by empirical analyses. This paper reports data from novel laboratory experiments designed to shed light on the campaign finance debate. Our experiment is based on a model where power-hungry candidates are motivated to trade favors for campaign contributions. Our data is consistent with the model's predictions. We find that voters' revise their beliefs in response to candidate advertising in a way that is consistent with theory. Moreover, in relation to privately financed electoral competitions, in publicly financed campaigns (i) high-quality candidates are elected more frequently, and (ii) margins of victory are larger. Both of these outcomes are predicted by theory. We conduct policy experiments on various campaign finance strategies, including the widely suggested caps on private fundraising. Our results suggest that caps can improve voter welfare but do not increase the likelihood that high-quality candidates will be elected.