According to a recent Economist/YouGov poll, Donald Trump leads the race for the Republican presidential nomination. Some 27 percent of registered GOP voters named the billionaire braggart as their first or second choice.

Trump’s supporters are more likely than other Republicans to associate with the Tea Party and to describe themselves as “very conservative.” But Trump’s appeal to them is rather surprising. Only a few years ago, he was a man of the Left, both in his own estimation and as revealed by the policy positions he took.