It is unlikely Donald Trump remembers what he was doing on Oct. 26, 1967. He was a student at the prestigious Wharton School of Finance, not having to worry about being drafted for the Vietnam War. Four student deferments – sought, not granted automatically – saw to that.

John McCain has vivid memories of that day. One of them may have been regret at having begged to be assigned combat duty instead of remaining in the Navy post he had for a time, as a public relations officer in Saigon.

It was on that fall day halfway around the world that McCain, flying a carrier-based jet, was shot down after dropping his bombs on a North Vietnamese power plant. McCain spent the next five-and-a-half years in the infamous “Hanoi Hilton” prison.

Now McCain is a U.S. senator from Arizona. Trump is a billionaire running for president. A few days ago, Trump said this of McCain: “He’s not a war hero. He’s a war hero because he was captured. I like people that weren’t captured.”

Many military veterans are right: Trump’s comment was a slur against those who, often after months or years of truly heroic service, became prisoners of war. Trump should apologize.

He should also apologize for saying in his campaign kickoff speech that Mexicans illegally entering the U.S. are “bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people.”

Trump just doesn’t get it. Clearly, the man who once bragged, “I’m, like, a really smart person” is not. Not at all.

And yet polls show him leading the field of Republican presidential candiates – up to 16 of them now. We hope that’s just a temporary, cynical backlash against political correctness.