WASHINGTON — Donald Trump has defied the laws of political physics from the moment he rode down that gold-toned elevator in his own Manhattan tower to announce his candidacy last spring.

Time and again he’s proved every pundit and all of his fellow Republican candidates wrong, and he remains the only GOP contender with a plausible chance to collect a majority of delegates before the Cleveland convention in July.

But after a year of hovering above the skyline like a giant dirigible, Trump is being brought down to earth by his most powerful enemy: his own need to demonstrate his masculine “strength” by disparaging others, particularly women.

It has taken a year for relevant, campaign-related examples to accumulate, but they reached critical mass just in time for a pivotal primary in Wisconsin next week that could see the start of a slow, steady decline in his chances.

He is simply so unpopular with female voters — who make up at least 54 percent of the turnout in presidential general elections — that a victory by him this fall seems all but impossible. In a new NBC News poll, Trump is viewed favorably by only 1 in 5 female voters. 

To be sure, his ratings among men aren’t dramatically better, and his main GOP rival, Sen. Ted Cruz of Texas, is almost as poorly regarded by women. Still, 1 in 5 doesn’t work.

“He can’t win, and women are a main reason why,” said Charlie Black, a Republican consultant advising Ohio Gov. John Kasich.

Trump critics also note that, despite his vow to ferociously attack Hillary Clinton in a general election, his salvos could be countered by Democrats as just another example of his corrosive attitude toward women.

There are plenty of examples already: his long-running firefight with Fox anchor Megyn Kelly, which included a veiled reference to menstruation; his high-school-level disparagement of Carly Fiorina’s looks; his vow to “spill the beans” on Cruz’s wife, Heidi; and Trump’s full-throated defense of his campaign manager, Corey Lewandowski, who was arrested this week in Florida and charged with using unwanted physical force to yank a female reporter away from his boss.

Trump’s own family and close advisers have been worried about Lewandowski’s short fuse and aggressive behavior for months, but Trump is sticking by him in the din.

Then, on Tuesday, Trump struck a match to the whole pile, telling MSNBC host Chris Matthews that women who get “illegal” abortions (and Trump wants to make them all illegal) should face “some form of punishment” — details unspecified.

In the hourlong face-to-face interview — no phone-ins this time — Matthews pressed Trump on whether he thought abortion should be illegal. The answer was “yes.” So if it is, should women be punished in some way? After hesitating several times, Trump answered “yes.”

After meandering around on the issue for years, Trump in the campaign has run as somewhat of a hard-liner: in favor of repealing Roe v. Wade and of banning so-called partial-birth abortions, but not endorsing a human life amendment or a ban on abortions even in cases of rape or incest.

But the comments to Matthews took him much further to the right, and away from the mainstream of female voters, 55 percent of whom think abortion should be legal in all or most cases.

Minutes after the taping of the show, and the airing of that key excerpt, the Trump campaign tried to walk the comments back, but it was too late. Democrats, liberals and leaders of women’s rights groups attacked with gusto.

So did Cruz, though his complaint came from the opposite political direction: that Trump was masquerading as a totalitarian foe of abortion, a role that rightly belongs to the Texan.

We’ll know soon enough whether Trump is on trouble, let alone going up in flames, when Wisconsin primary voters go to the polls on Tuesday.

The most recent poll, out on Wednesday and taken during the days that the Lewandowski story dominated the political news, showed Trump falling behind Cruz by 10 points.