Voters in general, and Christian voters in particular, express frustration with the lack of principle that characterizes most politicians, and the “flip flops” they engage in during election campaigns. Yet without winking at the lack of principles, it might help us to understand, and perhaps be a bit more forgiving, if we understand that the institutions of democracy themselves—and of U.S. democracy in particular—create incentives for politicians to behave the way they do. Some of these incentives can be changed; others most will not want to change, even if it would promise a change in the behavior of politicians.
Americans sometimes forget that the U.S. presidential election is not one election, but many. Not only do voters elect delegates to nominating conventions on a state-by-state basis, but the election to the presidency occurs through the Electoral College—chosen on a state-by-state basis rather than by a majority of the popular vote.
Politicians need to win what political scientists call the “pivotal” voter in order to be elected to office. In two-party majoritarian elections with a voters distributed along a regular “left-right” continuum, politicians must win the vote of the median voter. So their policy positions will tend to cluster around the policy preferences of the middle voter.