Republican voters have been seething with discontent at their party’s officeholders and have not become enchanted with any one of 15 more or less conventional politicians who are running. Democratic voters support their officeholders with lockstep loyalty and seem untroubled by the serious flaws of their party’s clear frontrunner.

This asymmetry helps explain some otherwise puzzling things. One is why polls have continued for several years to show the Republican party being disliked more than the Democratic party, even as both parties get roughly the same number of votes. The reason is that few Democrats express negative feelings about their own party, whereas many Republicans do.

Those negative feelings don’t, however, prevent Republicans from voting, however grudgingly, for even their party’s old-timers in general elections. Polls in 2014 showed the 70-something Senators Mitch McConnell and Pat Roberts, both members of Congress since the 1980s, in close races in heavily Republican Kentucky and Kansas. Yet both won with solid majorities and by double-digit percentage margins.