Donald Trump is like a box of chocolates. You never know what you’re gonna get, but it’s bound to be nutty.

After his slurring of Mexican immigrants as murderers, rapists and thieves bumped the billionaire blowhard to the top of GOP polls, The Donald must have felt like he could say anything and keep climbing.

And so, for no politically or personally defensible reason, Mr. Trump ridiculed the wartime service of John McCain. While the future Arizona senator spent five years being tortured in a Vietnamese POW camp, young Trump was collecting college deferments and preparing to inherit the real estate empire his father built.

“He’s not a war hero,” Mr. Trump said of Sen. McCain. “He’s a war hero because he was captured. I like people that weren’t captured.”

And I like people who keep their mouths shut when all they have to say is something stupid, but that’s not Donald Trump. Someone else he will never be: President of the United States.

The backlash from his McCain comments has caused Mr. Trump to backpedal a bit, but he did not apologize. Why should he? He keeps climbing in the polls. His celestial ego is crowding out the rest of the GOP field, none of whom has his star power or unflinching honesty.

The scariest thing about Forrest Trump — excepting maybe his angry orangutan haircut — is that he really seems to believe the nonsense he spews. It should be entertaining to watch Mr. Trump’s GOP rivals try to push him out of the race, which he can’t finish but is somehow winning.

Run, Forrest, run!