Elections from time to time are widely believed to carry a mandate, to express a message about changed policy preferences of the electorate. Whatever the accuracy of such beliefs—a matter about which we are skeptical—perceptions of a mandate should affect the behavior of actors in government. Politicians lack the scholarly luxury of waiting for careful analyses. They must act in the months following elections. We postulate that many will act as if the mandate perceptions were true, veering away from their normal voting patterns. This is driven by election results and interpretations that undermine old calculations about what voters want. As the flow of information gradually changes these perceptions, and the election becomes more distant, members of Congress return to their normal position. We first ask, how would members observe an emerging consensus of mandate? And then we model the duration of the change in behavior in an event-history framework. That permits a depiction of important movements of the median member and, from this, inferences about policy impact.