The effects of insulting political campaign rhetoric were examined in a laboratory setting. In Study 1, subjects categorized as for, against, or undecided about the issue of French language rights in English Canada read a political debate transcript focusing on this issue in which one candidate insulted or did not insult the other candidate. Backlash was evident on trait ratings: the insult source was rated more negatively in the insult condition than in the control condition, whereas ratings of the target were unaffected. Affective ratings of both candidates were lower in the insult condition than in the control condition. Subjects’ attitudes about French language rights also influenced their impressions of the candidates, but did not interact with the insult manipulation. In Study 2, subjects read debate transcripts embedded with insults that attacked either controllable target attributes, uncontrollable target attributes, or that contained no insults. The major findings of Study 1 were replicated, with the additional finding that insults directed at uncontrollable traits of the target produced effects in the same direction as but more extreme than those effects noted for controllable-trait insults. These findings are discussed in terms of political campaign tactics and the application of attribution theory to political person perception.