Republican presidential candidate Donald Trump, accompanied by his wife Melania Trump, speaks at a campaign event in Cedar Rapids, Iowa, on Feb. 1. (Mary Altaffer/Associated Press)

When a presidential election devolves into a hydrant-watering contest between leading contenders about the relative attractiveness of their respective wives, not only does the United States look ridiculous but also we diminish our moral standing to denounce other cultures’ marginalization of women.

It’s that bad.

This latest tantrum-a-deux between Donald Trump and Ted Cruz began with an anti-Trump ad targeting his wife Melania. Created by a super PAC unrelated to Cruz (and run by a woman), the ad showed a nude photograph of Melania Trump that was shot for GQ in 2000 when she was a model and before she became Mrs. Trump.

The ad, which ran on Facebook just before the Utah caucuses, read: “Meet Melania Trump. Your next first lady. Or, you could support Ted Cruz on Tuesday.”

Presumably, the image would so offend Mormon women that they’d vote for Cruz. Indeed, Trump lost. But one notes for fun that few if any wagered that the photo might also offend men, least of all Trump himself. Anyone who has lived a while recognizes Trump as the schoolyard braggart who might just as well distribute the photo himself to remind his locker-room tormentors that, hand size notwithstanding, he had won the prize.

Republican presidential contender Donald Trump is going after rival Ted Cruz's wife, Heidi. Here are other times he's insulted women, from Rosie O'Donnell to Hillary Clinton. (Sarah Parnass and Nicki DeMarco/The Washington Post)

The caption on a recent Trump retweet, featuring side-by-side photos of a posed and smoldering Melania and an unflatteringly candid Heidi Cruz, was: “The images are worth a thousand words.”

Is this what Trump means when he says he can be “presidential” when the time comes? Would it be impolite to ask when that might be?

The photo of Heidi Cruz, an extremely attractive, successful businesswoman, was obviously intended to make her look shrill and scolding, a shriveling image to most men. Plainly, it was one of those split-second expressions loathed by all who have been targeted by the vengeful eye of a roving camera.

Trump, whose compulsive tweeting surely leaves little time for self-reflection (or policy considerations), issued a warning to Cruz about the ad:

“Be careful, Lyin’ Ted, or I will spill the beans on your wife!”

There’s something unmanly about threatening a woman through a tweet, which has a nyah-nyah quality to it. Two little dickie birds sitting on a wall. . . . Come on, guys, get down from your perches and duke it out like men. (Can we still say that?) Mano a mano. Or at least face to face. Perhaps this is what prompted Cruz to call Trump a “sniveling coward” and to “leave Heidi the hell alone!”

There is also something unseemly about a woman using another’s racy image to discredit her, as though what is, in fact, a tasteful pose as such things go, were the extent of her value. Melania was a model — and now she’s a wife and mother. How about we also leave Melania the hell alone while we’re at it?

Once upon a time, I protested the Democratic trope that the GOP was waging war on women. Since the accusation was based primarily on the Republican Party’s continuing defense of the not-yet-born, amid absurd and offensive comments by a handful of GOP males whose tongues and brains have never met, I rejected the notion as little more than a political strategy.

Sue me if you must, but I’ve changed my mind.

Trump’s success is troublesome as a matter of common decency. He seems to recognize what decency sounds like when it involves his wife, but he’s coyly oblivious when he makes derogatory remarks about other women, including Megyn Kelly, Rosie O’Donnell and Carly Fiorina, to name a few.

Yes, he’s an equal-opportunity offender, a philosophy I respect, but his insults to women are of a particular sort, typically focused on looks and/or physiology. If this is presidential, we need a new definition. And if Republican men (and women) can’t bring themselves to condemn Trump for his disrespect toward women, then they are by their silence complicit in what feels a lot like a war on women by the Republican front-runner.

Should Trump become president, he likely will have defeated the only woman left in the race, Hillary Clinton, who is recognized globally for her work in raising the status of women. In that case, other nations may reasonably conclude that the United States doesn’t care much for women. Worse, they can congratulate themselves for keeping their own women in their swaddled places, deserving neither respect nor protection.

These and all other things considered, I’d rather hear from the wives of wannabe presidents than their husbands these days. This goes for the wives of presidents past as well.

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