The second problem is Donald Trump. He has thrilled many rank and file Republicans. Ron Brownstein of National Journal says the blue-collar, noncollege wing of the Republican primary electorate has “consolidated” around Trump. Chances are, these Republicans won’t cut and run from Trump any time soon, even when he tweets that Iowa Republicans who put Ben Carson ahead of him in a poll last week have “issues in the brain.”

That means Trump, with a solid base, could win the Republican nomination—not likely, but possible. That would probably be a disaster for the Republican party and the candidates for the House and Senate below Trump on the ballot. Trump’s negatives are so high his prospects of beating Clinton in the general election are very poor.

The rule of thumb for 2016 is that Republicans must increase their appeal to immigrant groups and minorities. Mitt Romney got 27 percent of the growing Hispanic electorate in 2012. To win in 2016, the GOP nominee needs roughly 40 percent or more. Trump, having insulted Hispanics, won’t get there. And the notion he would expand the white vote is a myth.