I have an uncomplicated theory of voter behavior: when the party in power approaches issues in a way that is simplistic, extreme and beholden to special interests, people tend to vote for the other party.

This theory explains a lot more than you might think. It explains why New York City—a place where you could spend all day without running into a single Republican—has elected and reelected quite a few Republican mayors. It explains why Massachusetts—arguably our most Democratic state—has a very popular conservative Republican governor. It explains why California—a state where successful Republican politicians are a vanishing breed—elected Arnold Schwarzenegger as governor.

And, it explains why traditionally Republican districts voted in the last election to give control of the House of Representatives to Democrats instead.

Let’s take a handful of issues that voters said were important in the recent election: say, health care, immigration, climate change and taxes. Forget what candidates said in the safe districts, where opinions are as extreme as they are irrelevant. Focus on what was said in the contested races.