Presidential campaigns always fear the October surprise. In Trump's case it was a pattern of demeaning behavior toward women that took on new significance after a weekend bracketed by two explosive reports.
CNN has not yet independently confirmed either The New York Times or People Magazine accounts. The Trump campaign described the entire Times article as a "fiction" that amounted to "character assassination." A Trump attorney also issued an open letter to The Times demanding an immediate retraction and apology. The Trump campaign told People magazine: "This never happened. There is no merit or veracity to this fabricated story."
Trump aggressively defended himself during a rally Thursday, saying they were "pure fiction," "outright lies" and promised to provide evidence to prove they were false.
"These claims are all fabricated. They're pure fiction and outright lies. These events never, ever happened," Trump said in West Palm Beach, Florida.
But at a time when voters are already casting their ballots and Trump's path to 270 electoral votes has dramatically narrowed, the campaign is engulfed in a swirl of allegations about Trump's conduct toward women that has crippled its ability to sway undecided voters.
Trump's assertion to CNN's Anderson Cooper in Sunday night's debate that his boasts on the "Access Hollywood" tape about grabbing women were "just words" -- seemed to inflame controversy.
Several women said his denial of those kinds of actions infuriated them and prompted them to come forward. As the floodgates opened on the conduct of a powerful and litigious figure, several beauty pageant contestants said they felt emboldened to describe Trump's leering, lewd behavior when he owned the Miss USA pageant. Tasha Dixon, a 2001 contestant, told a Los Angeles TV station, Trump entered rooms where "some were topless ... some were naked" as he allegedly inspected and appraised as the owner of the pageant.
First lady Michelle Obama said the comments in the 2005 video had left her "shaken."
"I can't stop thinking about this," she said at a rally for Hillary Clinton in Manchester, New Hampshire. "It has shaken me to my core in a way I could not have predicted."
Trump has retained his core support despite hits on his credibility. But this time the question is whether his loyal backers will believe that the wave of allegations are a calculated attempt by his enemies to destroy his campaign in the final weeks.
The problem he faces is that the conduct described by several women aligns exactly with the kind of behavior he bragged about in his own voice to "Access Hollywood" host Billy Bush in 2005.
A trio of state polls released this week -- taken after the 2005 recording was published -- show Clinton's northern "blue wall" holding,
as she carries commanding leads across a series of key states: She leads Trump by 9 points in Pennsylvania, 11 points in Michigan and 7 points in Wisconsin.
Additionally, a Republican National Committee source told CNN's Sara Murray Thursday that the Trump campaign decided to pull resources from the swing state of Virginia, essentially conceding the state to Clinton.
"We remain absolutely committed to winning in Virginia. While we're reallocating some of our staff strategically to accommodate early voting in nearby priority states such as North Carolina, our campaign leadership and staffing remains strong in Virginia," said John Ullyot, a Trump spokesman, in response to the reports the campaign was pulling out of Virginia.
Trump is now in the foxhole, lashing out at Republican lawmakers like House Speaker Paul Ryan, who refuse to defend him, questioning the credibility of his accusers, and excoriating what he views as a biased press corps that he believes is aiding Clinton.
"You're a disgusting human being," Trump reportedly told New York Times reporter Megan Twohey when she asked him about the allegations that he touched women inappropriately before publishing the story. "None of this ever took place," he told the newspaper.
The Trump campaign's strategy as each accusation surfaced has been to shift the conversation back to the allegations of sexual misconduct by Bill Clinton (who is not on the ballot), and his charge that Hillary Clinton served as an enabler who tried to damage the credibility of women he was involved with.
Speaking in Orefield, Pennsylvania, on Thursday, Trump's running mate, Indiana Gov. Mike Pence, called the women's accounts "unsubstantiated allegations" and said the Trump campaign is "not going to allow the Clinton campaign and the national media to turn this campaign into a discussion of slander and lies."
But Trump's stunt of trotting out several of Bill Clinton's accusers at the debate made many Republicans cringe.
Throughout this campaign, Trump has laid out a clear, populist message and set of goals. Nearly any voter, on the other hand, will tell you they aren't sure what Clinton's core message is or what her agenda would be in the White House.
But in these final weeks, when Trump should be making his closing argument, the deluge of scandals surrounding his campaign have swallowed his message. As the polls make clear, Clinton has benefited -- that effect has elevated her flawed candidacy to something close to a sure bet.
"You know, if I were running against any Republican, I would be working hard and I would be asking for your help," Clinton said at a campaign event Thursday. "But this is an election between two very different visions, views, and sets of values. And that's why the stakes are so high, because we know, we've already learned who Donald Trump is, what we have to prove in this election is who we are, and what we stand for, and what we believe in."
Losing campaigns often try to pinpoint the definitive moment when they knew the race was over.
For John McCain, it was the day the markets collapsed and he insisted the fundamentals of the economy were strong. For Mitt Romney, it was the emergence of a taped fundraiser speech where he said 47% of American voters would never vote for him because they are dependent on government.
It will not be quite as simple to pinpoint one single moment for Trump if he loses on Election Day, because his polls numbers have been sliding ever since his defensive and unpolished performance in the first debate.
"For many voters still struggling with how to vote, all the bad news about Trump -- combined with the questionable things he has personally said over the last 16 months -- have finally created a tipping point that many thought would have come much earlier," said Republican strategist Mike DuHaime, who has advised New Jersey Gov. Chris Christie and former president George W. Bush.
DuHaime called the Trump campaign's decision to attack Bill Clinton as their response "ludicrous and amateurish," an illustration that "they only understand how to talk to the people already voting for Trump."
"With all of the places where Republicans could legitimately question Hillary Clinton's policy choices" such as her approach to Russia, Syria, tax policy and her US Senate votes, as well as "her overall judgment" in creating her own private email server and the questionable fundraising practices of Clinton Global Initiative, "our nominee has decided to attack her husband instead," he said.
"Maybe it feels good for them to vent 20 years of anti-Bill frustrations but it doesn't help Trump and likely helps Secretary Clinton," he said.