Watch the second presidential debate tonight at 9 p.m. ET on CNN and CNN.com.

St. Louis CNN  — 

Here’s the great irony of the 2016 campaign: Rather than a historic debate about whether a female nominee can best her male rival, the race is suddenly a referendum on how much crass, coarse objectification of women America is willing to take.

When Hillary Clinton clinched the Democratic nomination, it was hailed as a barrier-breaking moment for women. Young and old supporters watched her acceptance speech in Philadelphia with tears streaming down their cheeks, describing themselves as witnesses to history.

But the sweeping stagecraft of the #ImWithHer convention now seems like a quaint memory. With the emergence of the 2005 “Access Hollywood” tape featuring Donald Trump bantering about unwanted advances and actions that would constitute sexual assault, the 2016 conversation about women moved straight into the gutter.

“One of the most disturbing things about this election is just the unbelievable rhetoric coming from the top of the Republican ticket,” President Barack Obama said Sunday, noting he wouldn’t repeat the language because “there are children in the room.”

The 2005 tape has thrown the Republican Party into disarray, shattering the fragile alliance of GOP support around him, as dozens of top lawmakers and officials announced they could not stand behind what they viewed as sexist and misogynistic comments. His taped apology, many of them said, was not enough.

Now it’s up to Trump to use Sunday’s debate in St. Louis, co-moderated by CNN’s Anderson Cooper, to try to rescue his flailing campaign.

We really don’t know yet what the true political fallout will be of Friday’s bombshell report on the tape, which was published by The Washington Post. But we know that it came on the heels of a horrific two weeks for Trump during which he flubbed his first debate performance, engaged in a Twitter-shaming feud with a former Miss Universe and defended the notion that he may not have paid federal taxes over an 18-year period.

What to watch in the second presidential debate

In short, Clinton was on the upswing. She was inching up in critical battleground states like Ohio and Pennsylvania, areas that Trump had once hoped would be his firewall.

She was also consistently leading (by double digits) Trump among what may be the most critical demographic in this presidential election: white, suburban, college-educated women.

But it’s also worth remembering that Clinton remains a deeply flawed candidate. Her dominance among women in polling often masked the deep reluctance I hear from women who were supporting her on the campaign trail.

Some of the most fascinating conversations were with the many young Democratic women supporting Bernie Sanders who were offended by the suggestion that Clinton’s gender should be a factor in who they voted for. The response I often heard, particularly from millennial women, was: “Aren’t we past that?”

Clinton is widely distrusted and disliked. Many women say in interviews they do not feel they can relate to her.

But she has been paired with a rival in Trump who has said more offensive things about women than any nominee in recent memory. And that may be Clinton’s saving grace this year in a race that for a time looked as though it might be very close.

Kaine: Expect voters to ask Trump about vulgar remarks

Sure, Clinton’s election as president might be a historic first, but the force driving many women to the polls will be their disgust with Trump.

The “Access Hollywood” tape – where Trump boasted about popping Tic Tacs before kissing random strangers, and groping attractive women by their genitals because you can do anything as a star – was really a bookend to a campaign that began with his exchange with Fox News anchor Megyn Kelly, who asked him during the first GOP primary debate to defend his past descriptions of women as “fat pigs, dogs, slobs and disgusting animals.”

Many Trump supporters fiercely defended him, brushing off his critical comments about women as being part of his show biz persona, the kind of behind-the-scenes banter one would expect to hear at a Miss Universe pageant.

“Men at times talk like that,” former New York Mayor Rudy Giuliani told CNN’s Jake Tapper Sunday on “State of the Union,” while admitting that what Trump described in the video constituted sexual assault.

New revelations emerged Saturday after CNN’s Kfile reviewed hours of newly uncovered audio of demeaning conversations Trump held over a 17-year period with radio shock jock Howard Stern. The topics discussed included his daughter Ivanka’s physique, having sex with women during their menstrual cycles, threesomes, and checking out of relationships with women after they turn 35.

From the beginning, Trump adeptly framed his campaign as a revolt against “political correctness,” which meant no apologies for his past comments about his antagonists, like Rosie O’Donnell, or his critiques of the form and figure of women like former Miss Universe Alicia Machado.

Trump voters stay loyal: ‘I am not voting for him to be pope’

As the press explored the long historical record of Trump on tape, the campaign at times felt like a flashback to the “Mad Men” era, particularly in the midst of the dramatic demise of Fox News Chief Roger Ailes, a close friend of the real estate magnate who went on to advise his campaign.

Trump used words and phrases on the campaign trail that no one had heard before from a politician. Political taboos were to be mocked and broken. The premium was on shock value, and his crowds loved it. Every time pundits predicted Trump’s comments would lead to his demise, he proved them wrong.

But this time, members of Congress have threaded their statements of condemnation of Trump with mentions of their wives, daughters, sisters and mothers.

The 2005 “Access Hollywood” tape has brought us into unchartered territory. It’s the place where you wonder whether Trump’s reign as “Teflon Don” might be over.