Just who are Donald Trump's supporters?

“Actually, I won everything,” Donald Trump said this week, after his victory in South Carolina and before his rout in Nevada.
 “I won short people, tall people. I won fat people, skinny people. I won highly educated, okay educated, and practically not educated at all. I won the evangelicals big and I won the military.”
 The Republican presidential frontrunner was, broadly speaking, correct. After his third consecutive victory, one that puts him on course to win the Republican nomination for the White House, it is less useful to ask who is voting for him than who isn’t. The only state he didn’t win was Iowa, where he came second. In New Hampshire; South Carolina; and, on Tuesday, Nevada, Trump did not just win resoundingly by leveraging one or two types of conservative voter. Entrance polls reveal he triumphed by drawing on a pool of voters as wide as it was deep. Who are Trump supporters?
 Insofar as the Republican electorate goes, the answer, for the moment at least, seems to be everyone.