Eligible voters have been coordinating their turnout and vote decisions for the House of Representatives in midterm elections. Coordination is a noncooperative rational expectations equilibrium. Stochastic choice models estimated using individual-level data from U.S. National Election Studies surveys of the years 1978–1998 support the coordinating model and reject a nonstrategic model. The coordinating model shows that many voters have incentives to change their votes between the presidential year and midterm after learning the outcome of the presidential election. But this mechanism alone does not explain the size of midterm cycles. The largest source of loss of support for the president's party at midterm is a regular pattern in which the median differences between the voters' ideal points and the parties' policy positions have become less favorable for the president's party than they were at the time of the presidential election (nonvoters show the same pattern). The interelection changes are not consistent with the theory of surge and decline.