While 26 percent of Republicans say they would never vote for Trump, only 11 percent of Democrats say they would never vote for Clinton. Democrats don’t have the same kind of ideologically pure wing that has hurt GOP presidential candidates in the past. Democrats, it seems, are more practical. They may prefer Bernie Sanders, or one of the others, but when push comes to shove, almost all of them will vote for Clinton. Why? They want to win.

I recently received an e-mail from someone named Carl who described himself as a conservative Christian, and he wrote, “I have voted Republican since Eisenhower beat Stevenson, and if Jeb, Christie, Kasich, or Graham are nominated, I WILL STAY HOME!” 

Carl is not alone. I received similar e-mails during the last two presidential campaigns and millions of the ideologically pure — who normally would vote Republican — did in fact sit home, if not handing the elections to Barack Obama, at least making it a lot easier for him to win.

These purists have told me that there’s little or no difference between a moderate Republican and a liberal Democrat. They’re delusional, of course, blinded by their hard-right ideology, but that’s what they believe nonetheless. And depending on who the GOP nominee is, they could represent big trouble for the party.