To date, field experiments on campaign tactics have focused overwhelmingly on mobilization and voter turnout, with far more limited attention to persuasion and vote choice. In this paper, we analyze a field experiment with 56,000 Wisconsin voters designed to measure the persuasive effects of canvassing, phone calls, and mailings during the 2008 presidential election. Focusing on the canvassing treatment, we find that persuasive appeals had two unintended consequences. First, they reduced responsiveness to a follow-up survey among infrequent voters, a substantively meaningful behavioral response that has the potential to induce bias in estimates of persuasion effects as well. Second, the persuasive appeals possibly reduced candidate support and almost certainly did not increase it. This counterintuitive finding is reinforced by multiple statistical methods and suggests that contact by a political campaign may engender a backlash.
Bailey, Michael, Daniel J. Hopkins, and Todd Rogers. "Unresponsive and Unpersuaded: The Unintended Consequences of Voter Persuasion Efforts." HKS Faculty Research Working Paper Series RWP13-034, September 2013.