An anti-Donald Trump Super PAC is running ads to try to convince Mormons not to vote for Trump — by slut-shaming his wife, Melania.

And Trump hit back Tuesday night with a bizarre tweet vaguely threatening Cruz's wife:

Lyin' Ted Cruz just used a picture of Melania from a G.Q. shoot in his ad. Be careful, Lyin' Ted, or I will spill the beans on your wife! — Donald J. Trump (@realDonaldTrump) March 23, 2016

What "beans" might those be? It's not at all clear.

But Cruz wasn't actually responsible for the ad. BuzzFeed News reports that Make America Awesome, founded by Republican strategist Liz Mair for the purpose of "blocking and reversing Donald Trump's political ascent," released the ad to try to increase turnout among members of the Church of Jesus Christ of Latter-day Saints ahead of the Utah primary on Tuesday.

Most LDS voters are Republican, but they strongly dislike Trump for his crude behavior and his hard-line stances against immigration and Muslim religious freedom.

Make America Awesome is trying to convince Mormons to vote for Ted Cruz instead, using three ads. One features Mitt Romney urging voters to support the Republican who can beat Trump in their state. Another highlights Trump's history of pro-choice views (which he now says he has "evolved" away from).

The third ad, however, features Melania Trump posing nude and mocks the idea that she could be the first lady one day. The photo comes from a shoot Melania did for British GQ in 2000.

Melania Trump studied architecture and design at the University of Ljubljana in Slovenia before becoming a successful fashion model. She speaks five languages fluently and has her own jewelry and cosmetics lines. Barbara Walters, after interviewing her, said, "Maybe because she's so beautiful, we don't expect her to be as smart as she is."

But people who see this ad might not know any of that, and might be inclined to judge Melania Trump negatively because of how she's portrayed. The ad plays on unfortunate stereotypes about women who pose nude or are open about their sexuality: that they're vapid, can't be trusted, and shouldn't be respected. It attacks Trump not by attacking him directly, but by impugning the character of the woman he decided to marry.

And sadly, it's a tactic that might appeal to some socially conservative voters.

Update: Make America Awesome's Liz Mair objected to the idea that the ad was "slut-shaming" Melania Trump, and also said she objects to the word "slut" in any context. The ad would appeal to Mormon women not because it suggests anything about Mrs. Trump's sexual proclivities, Mair said, but because Mormon women wouldn't like the "typical porn/porn-lite" message of "female subservience" in the picture.

"The fact is, the image in the ad — for which Melania Trump apparently willingly posed and has long been widely available online — isn’t objectionable because she’s nude or because it implies she’s ‘promiscuous’ (which, by the way, it doesn’t, though it does suggest she may have bigger hands than Donald)," Mair wrote in an email. "It’s objectionable because in typical porn/porn-lite fashion, it features her handcuffed to a briefcase, looking vulnerable and sends an implicit message of female subservience, as a lot of photos of tethered, naked women produced for male titillation and consumption do. And Mormon women don’t much like that."

Donald Trump's ideology of violence