WASHINGTON — Yet again, Donald Trump stole the show.

In the first GOP debate, he refused to pledge support for the eventual nominee and, as a fitting bookend, in the third and final general election debate, he refused to pledge to concede if he loses fair and square.

He called Hillary Clinton a "nasty woman," an epithet that only reinforced a major political vulnerability stemming from his lewdness and his habit of judging women, in public, based on their looks.

{"type":"video","title":"Dallas News Video","author_name":"Dallas News","_id":"swNDl2NjE6wtqb2NmRzg7lisSelozy83","provider_name":"Ooyala","html":"

","providerType":"ooyala","providerLink":"http://www.dallasnews.com/oembed","embedType":"video"}

But Clinton did more than stand aside as Trump self-immolated before a national television audience. She fanned the flames and simply out stamina-ed and outsmarted him.

"Every time Donald is pushed on something which is obviously uncomfortable, like what these women are saying, he immediately goes to denying responsibility," she said when talk turned to fitness for office and the nine women who have accused Trump of unwanted sexual advances. He insisted in the second debate that boasting about unwanted sexual advances was mere "locker room talk."

"He never apologizes or says he's sorry for anything," Clinton added.

She spoke of "a pattern of divisiveness, of a dark and in many ways a dangerous vision" that includes relishing the jostling and fisticuffs at his rallies. She needled him for using Trump Foundation funds to purchase a six-foot portrait of himself.

"Who does that?" she mocked.

Clinton linked two of his favorite issues, a push to cut taxes on the wealthy and to erect an impermeable wall along the U.S.-Mexico border, and you could almost see Trump's id, the Mr. Hyde he'd suppressed so effectively in the first half of the debate, surfacing.

"We have undocumented immigrants in America who are paying more federal income tax than a billionaire. I find that astonishing," she said.

The boiling point came during a snippy episode of cross talk, a duet of venom. Clinton's part: "He has all these conspiracy theories which he's been spouting. ... He says he's unshackled. I think he's unfit, and he proves it every time he talks."

Trump refused to pledge to respect the wishes of voters on Election Day. "That's horrifying," she said, launching into a carefully crafted diatribe highlighting times he claimed he was the victim of rigging: when he lost the Iowa caucus and the Wisconsin primary, when Trump University faced lawsuits.

"There was even a time he didn't get an Emmy," she said, belittling him both as a whiner and a reality TV star.

"Should have gotten it," Trump said, playing into her hands.

"This is a mind-set," Clinton shot back. "It's funny, but it's also really troubling. That is not the way our democracy works. We've been around for 240 years, we've had free and fair elections, we've accepted the outcomes when we may not like them, and that is what must be expected of anyone on the debate stage in the general election."

Trump needed a game-changing performance. It was a substantive debate for quite a while, but in the end, he got played.