Degrees of Disrespect: How Only Extreme and Rare Incivility Alienates the Base

When evaluating their own politicians, do partisans tolerate or punish the incivility now common in political discourse? While the answer is crucial to understand rising incivility, prior findings are mixed. I propose that copartisans tolerate milder degrees of incivility, which out-partisans punish, but that a limit exists beyond which the rhetoric becomes too extreme for even the base. Consequently, to examine whether copartisans tolerate or punish the incivility in current discourse, we must compare (1) how strong of an incivility they will tolerate to (2) how strong the incivility in current discourse is. To make this comparison, I develop a method integrating survey experiments with crowdsourced content analysis, which maps stimuli onto the distribution of online incivility among Congress members. I find that copartisans tolerate typical degrees of incivility, as the incivility in current discourse is rarely so extreme that favorability among copartisans drops. However, typical degrees lower out-party favorability, reinforcing polarization.