"The great majority of those who voted for Donald Trump in the 2016 general election also voted for Romney in 2012. Similarly, the great majority of those who voted for Clinton in 2016 voted for Obama four years earlier. There was no massive voter defection on either side. For the most part, traditional party loyalties held firm. Nevertheless, there were some significant shifts at the margins, and when these marginal shifts are enough to produce a surprising presidential win then they tend to be of interest. Some of the voters most likely to shift from Obama 2012 to Trump 2016—and to vote for Trump in the GOP primary that year—were white working-class, non-college educated voters in Rust Belt small-town counties. These voters tend to be center-left on economics but conservative on cultural issues: the classic populist position. These are also the voters who allowed the 2016 GOP nominee to win over a national electoral majority in key states such as Pennsylvania, Michigan, Wisconsin, and Ohio. They are to the right of the GOP donor class on immigration, but to the left of it on pocketbook issues such as Social Security and economic inequality. Viewed in aggregate, their politics are quite literally center-right. But the specific way in which they are center-right is the precise opposite of upper-income Republican elites, who tend to favor strict conservative economics combined with more open immigration. Naturally these substantive policy differences produce intraparty tensions, once brought out into the open. And so they have."