Donald Trump is an early riser. Around 5:30 a.m. Eastern Time Friday he went on one of his famous tweetstorms, attacking former Miss Universe Alicia Machado as “disgusting,” a “con,” and even making references to a sex tape. How did those 16 Republicans lose to this guy again?

Easy. By not knowing they had the antidote in hand the whole time. It isn’t Trump University or his failed casinos or his personal piggy bank of a foundation. His supporters—even the white Evangelical ones—truly don’t care what he has done or to whom he’s done it. Trump’s real Achilles heel, and the thing most likely to keep him out of the White House, is his brazen contempt for women (plus his lack of impulse control and inability to stay off his Android phone).

Know that if Kellyanne Conway batch deletes those tweets by noontime, the screenshots will live forever, probably in campaign ads by 12:30. And it’s not just the manic tweeting.

Three times now, women in debates have forced Trump to confront the ugly things he has said over the years about women he doesn’t deem beautiful enough, fit enough or compliant enough for his gilt-laden standards. And three times, Trump flailed: onstage with Carly Fiorina, whose “face” he had insulted; facing off last August against moderator Megyn Kelly, who had challenged Trump for calling women “fat pigs,” “dogs,” and more; and again this week in that sniffle-filled, verbal Kamikaze mission against Hillary Clinton.

Indeed during Monday night’s kick-off presidential debate, Clinton skillfully exposed and exploited Trump’s seeming inability to control his boorish attitude toward women.

Of all of the preparation Team Clinton did, purportedly including drawing up a psychological profile of the erratic businessman, perhaps the most valuable thing it did was memorizing that moment from the first Republican debate. Hillary Clinton threw roughly the same punches Monday night that Kelly did, and Trump’s retort as he interrupted Clinton—something he did more than 50 times in 90 minutes—sounded familiar.

Trump took Clinton’s bait over and over in the debate. Responding to Lester Holt’s reminder that he claimed Clinton doesn’t have that presidential look, he spat out: “she doesn’t have the look, she doesn’t have the stamina”; repeating the word “stamina” over and over again as if he was auditioning for a Viagra ad.

And when Clinton dropped a clearly planned anecdote about his shaming of former Miss Universe Alicia Machado for gaining weight after winning the beauty contest in 1996, Trump seemed to come undone. He sputtered and spattered and demanded to know, “Where’d you find her?” Turns out the Clinton team had an online ad about Trump’s berating of Machado up by the time the debate wrapped. And then of course Trump compounded matters Tuesday morning to his pals at Fox & Friends.

Trump’s woman trouble is not exactly surprising. He’s running against the potential first woman president. And despite the intractable nature of Clinton Derangement Syndrome in a big chunk of the American electorate, Clinton is exceeding normal Democratic polling among white women, particularly white college -educated women, while holding Democrats’ traditional and huge margins among women of color. Mitt Romney carried white women by 14 points in 2012, and George W. Bush racked up an 11-point margin in 2004. John McCain, saddled with Sarah Palin, did less well—just 7 points—but he still won.

Clinton is currently up 16 points in the new ABC/Washington Post poll with white women (versus being down 13 points with white men), and she leads among white college-educated women by a whopping 31 points. Clinton even leads among white women without a college degree, by 8 points. If those numbers hold, Clinton would be the first Democrat to carry a majority of white women since her husband did so in 1996.

Even without the euphoria of “yes we can,” Hillary Clinton is to white women what Barack Obama was to African-Americans. She represents the opportunity to see a like image in the Oval Office for the first time. That has to be tempting even for Republican women who would never support a Democrat, let alone a Clinton, and Trump’s demeanor and debate performance is making it easier for white independent and even Republican women to cross over.

And Trump is uniquely vulnerable because his record of insulting and demeaning women is as long as his love of Putin’s Russia is deep. According to the documentary Trump: What’s the Deal, he verbally harassed first wife Ivana, before dumping her for Marla Maples, whom he resisted marrying in a most public and embarrassing way, only to dump her and marry Melania before reportedly berating her for not losing her baby weight fast enough after giving birth to their now-10-year-old son Baron. The most effective Clinton ads this season have been the ones showing women and girls listening to Trump’s cruel words in his own voice.

Trump is at further risk due to his almost limbic inability to control himself when attacked, particularly by a woman. Consider that there’s no one who gets under his thin skin the way Elizabeth Warren does. She and New York Times columnist Maureen Dowd have shared the sobriquet “goofy” as stars of Trump’s infamous Twitter tirades—though Warren has the smear “Pocahontas” all to herself.

During the campaign, Trump has gone after white women, Latinas (Machado and Susana Martinez, the governor of Mexico), Asian-American and Muslim women (Gold Star Mother Ghazala Khan). His Fox News chest thumping at a black Flint, Michigan pastor, Faith Green Timmons, came a day after he sheepishly backed down when she stopped him from politicking in her pulpit. Interestingly, he has yet to have a go at Michelle Obama, who just cut a national ad for Hillary Clinton. One can only imagine how that might go.

The one woman Trump does seem to totally respect is his daughter from his first marriage, Ivanka, on whom he heaps constant, effusive, at-times borderline creepy praise and physical affection. Trump has given Ivanka extensive control over both his business and his campaign, even agreeing to put a mothers-only parental leave plan into his campaign plank at her behest. When allegations of sexual harassment beat a path to his door, it was Ivanka who was sent out to publicly refute them.

Team Trump clearly understands his vulnerabilities. It’s no coincidence that while Hipster Nazi stenographer Steve Bannon was named the campaign CEO, the campaign manager and public face is Kellyanne Conway, a respected pollster who reportedly got the job by speaking softly to “Mr. Trump,” and giving him bad news in the way a mother might cajole an obstinate child. Team Trump deploys a small army of female spokespeople, including Katrina Pierson, Hope Hicks and Apprentice alum Omarosa Manigault to flack for him on TV.

Despite that, he is likely to get his proverbial clock cleaned at the hands of women in November, meaning he’ll need to run up historic margins with white men in order to get to 270.

Democrats have arguably underplayed questions of Trump stiffing the little guy, from employees to contractors he has done business with. And clearly, Trump is extremely vulnerable to questions about his wealth, which is why Team Clinton trolled him by putting confirmed billionaire Mark Cuban in the audience at Hofstra.

But Trump has telegraphed his real weak spot over and over again. He is incapable of reconciling his relationship with women to the modern world. He cannot stop himself from lashing out at female rivals, and he cannot hide his disrespect for half the human population.

To be sure, Hillary Clinton needs to add an affirmative case for herself to the negative case against Trump, including with women—younger women and women of color in particular—who might not be as motivated to vote as Trump’s eager followers. But with just weeks to go before Election Day, and with women typically voting in larger numbers than men, Democrats have a Trump trigger they can pull again and again.