Many years ago, I heard one of the Republican Party’s strategists, Alex Castellanos, explain elections as offering voters a chance to use the gas or the brakes. In times when voters dislike the direction their leaders are taking them, they can hit the brakes. When they want to continue further down the road they’re on, they can hit the gas.

In 2013, at an event at the Brookings Institution, Castellanos described it in this way: