Midterm elections don't come with the same sort of intensity and attention as, say, presidential campaigns. But this year's midterms, in which Republicans retook the Senate in an absolute bloodbath for Democrats, are a bit of a headscratcher. This excellent tweet from FiveThirtyEight's Ben Casselman perfectly captures this.

Casselman's right. Let's recap:

Republicans won big in the 2014 elections. They captured the Senate and gained seats in the House. But they didn't do it by running to the right. They did it, to a surprising extent, by embracing ideas and standards that came from the Left. I'm not talking about gay marriage, on which Republicans have caved, or birth control, on which they've made over-the-counter access a national talking point. I'm talking about the core of the liberal agenda.

Voters: They move in mysterious ways.