Out: Cruz challenging Trump to a debate. In: Cruz challenging Trump to a duel.

Plenty has been written today about how obnoxious this retweet is. Less has been written about how stupid it is.

https://twitter.com/realDonaldTrump/status/712850174838771712

The last thing this guy should be doing, with a legit chance to close out the race before the convention, is handing Cruz free sympathy points and easy opportunities to make himself look good by defending his wife. “Dumb” doesn’t begin to describe it, especially given how piss-poor Trump’s polling with women is. I try to resist the conventional wisdom that he’d be a pushover for Hillary in the general election but his numbers with women are a hard argument to counter. And here’s the key: There’s no reason to think Trump will turn this around. On the contrary, there’s reason to think it might get worse, assuming these figures aren’t already rock bottom.

Trump’s favorability with women overall is a dismal 21 percent positive/ 70 (!) percent negative.

With men, it’s 28 percent positive/ 59 percent negative.

And while women traditionally vote for Democratic candidates in larger numbers than men, data shows that a Trump nomination would exacerbate the issue for Republicans.

Asked if they would prefer to see a Democratic president or a Republican president regardless of who the nominees are, 52 percent of female voters chose the Democratic option while 36 percent chose the Republican option. That’s a net advantage of 16 percentage points for the Democratic candidate.

Among Republican women specifically, a near-majority of 47 percent say they can’t see themselves supporting Trump. Just 32 percent say so about Cruz. Why might those numbers get worse? Because, as all of us realize perfectly well, the odds of Trump not taking a shot at Hillary Clinton at some point this fall along the same lines as the one he just took at Heidi Cruz are zero. He’ll say something, or retweet something, about her looks or about women being too soft to lead the military or some other stupid sexist remark and the media will run with it for two weeks and that’ll basically wrap things up. It’s this guy’s great misfortune to be running against the would-be first woman president, when the opposition will need to be extra careful about alienating women voters. Instead we’re about to nominate the one guy in the field more prone to alienating them than anyone else. Don’t underestimate the chance that that argument will move delegates Cruz’s way at the convention either. Some delegates will oppose Trump simply because he’s not a conservative but others will back him so long as they think he’s the GOP’s best chance to win in the fall. Convince them that he’s not and those votes are gone too. And given that all of what I’ve just said is very obvious, the fact that Trump would allow himself to swipe at Cruz’s wife anyway suggests this is a matter of pure indiscipline on his part. He can’t restrain the urge to take a cheap shot. It’s hard to believe that’s going to cost him when you’re viewing the race through the prism of a Republican primary, when there’s never a price to be paid for “political incorrectness.” But when the electorate expands, it’s going to cost him. The question is how much.

It’s costing him already, as a matter of fact. His old pal Megyn Kelly raised a virtual eyebrow this morning at his shot at Heidi Cruz. I assume you’ll be hearing more about that on tonight’s show. Kate Bolduan of CNN went after one of Trump’s advisors this afternoon when he came on to try to defend what Trump did. Watch the second clip below, especially the end. This is only going to get worse.