ST. LOUIS — Nearly every presidential debate gets billed as the make-or-break one. They usually aren’t.

But the one in St. Louis on Sunday really might be.

It comes after Donald Trump’s widely panned performance against Democratic former Secretary of State Hillary Clinton in the first debate Sept. 26, which raised anew questions about his knowledge and temperament. Post-debate polls gave Clinton that contest by a most 3-to-1.

That was followed by the worst week in Trump’s campaign and one of the worst in presidential campaign history — fat-shaming, porn talk, a devastating tax revelation and the forced suspension of fundraising by his charitable foundation.

Then came Friday afternoon’s bombshell release of audio from 2005 in which Trump brags about trying to seduce a married woman, groping women and getting away with it because of his fame.

All of which adds up to a must-win imperative for Trump when he takes the stage at Washington University for the second of three scheduled debates.

“I would call it more ‘make’ than ‘break,’ because he’s going to have to overcome that first debate,” said political scientist Dave Robertson of the University of Missouri-St. Louis. “The stakes are higher this time because Trump did so badly last time … and in the week that followed.”

It was a week in which Trump, picking up a thread from the first debate, fat-shamed a former beauty queen; falsely alleged she had a sex tape and implored people to view it; alleged without any evidence that Clinton was an unfaithful wife; physically mocked Clinton’s near-collapse from a bout of pneumonia; faced a revelation he lost $916 million in one year and may have avoided taxes almost two decades as a result; and was ordered by New York his to stop fundraising by the Trump Foundation because of improper certification.

There will be a final opportunity for redemption at the third debate Oct. 19 in Las Vegas. But if Trump sets in stone the bullying, policy-bereft narrative of his first debate by repeating it in St. Louis, he may be unable to rewrite it in the four weeks left before Election Day.

For Clinton, the danger Sunday is that Trump will listen to both friends and foes who marveled at how many attack opportunities he missed in their first outing.

To everyone’s surprise, Trump said little or nothing about Clinton’s vulnerabilities, including her handling of sensitive emails as secretary of state, the Clinton Foundation’s alleged conflicts of interest and her labeling of half of Trump’s supporters as “deplorable” bigots. The word Benghazi was never uttered.

Whatever mistakes Trump might repeat Sunday, he’s unlikely to repeat that one. He said as much in a post-debate interview on Fox News last month.

“(Moderator Lester Holt) didn’t ask her about the emails at all. He didn’t ask her about her scandals. He didn’t ask her about (Benghazi). They were leaving all of her little goodies out,” Trump said. In the second debate, he said, “I may hit her harder in certain ways.”

Friday’s leak of what appeared to be excerpts of Clinton’s paid speeches and emails from her campaign chairman, John Podesta, are potential fodder for Trump.

At the end of the first debate, Trump congratulated himself on not raising the issue of former President Bill Clinton’s sexual controversies — which, of course, in effect raised the issue. He has since hinted that, in the second debate, he might go there.

“Hillary Clinton was married to the single greatest abuser of women in the history of politics,” Trump told the New York Times. “Hillary was an enabler, and she attacked the women who Bill Clinton mistreated afterward … (I)t’s something that I’m considering talking about more in the near future.”

Establishment Republicans are terrified he will make good on that threat in Sunday’s debate. One called it “the course of action you take when you’re trying to lose an election.”

“There’s no adviser around Trump who is recommending this as a good course of action,” Republican strategist Brian Walsh told The Hill last week. “It takes you off your core message and into a very sensitive issue that would only exacerbate the gender gap at a time when he’s having serious problems getting support from female voters.”

By midweek, that warning seemed to have gotten through, with Trump telling the New York Post that he was back to swearing off the topic. “I want to win this election on my policies for the future, not on Bill Clinton’s past,” Trump said in an email to the paper.