The charges leveled against him emerged in the supercharged thick of the 2016 campaign, when there was so much noise and chaos that they were just another episode for gobsmacked voters to try to absorb - or tune out.
"When you have a Mount Everest of allegations, any particular allegation is very hard to get traction on," says political psychologist Stanley Renshon.
And Trump's unconventional candidacy created an entirely different set of rules.
"Trump is immune to the laws of political physics because it's not his job to be a politician, it's his job to burn down the system," says Eric Dezenhall, a crisis management expert in Washington.
Now Alabama Senate candidate Roy Moore, accused of assaulting teenage girls when he was in his 30s, is waving that same alternative rulebook.
Long a bane to establishment Republicans, Moore is thumbing his nose at calls by Senate Majority Leader Mitch McConnell and other GOP members of Congress to drop out of the campaign, and accusing them of trying to "steal" the race from his loyal insurgents.
As for Trump, the president who rarely sits out a feeding frenzy is selectively aiming his Twitter guns at those under scrutiny.
He quickly unloaded on Democrat Al Franken after the Minnesota senator was accused Thursday of forcibly kissing and groping a Fox TV sports correspondent, now a Los Angeles radio anchor, during a 2006 USO tour.
Yet Trump has been largely mum as Washington Republicans try to figure out what to do about Moore. McConnell and company have zero interest in welcoming an accused child molester to their ranks nor in seeing their slim 52-48 Senate majority grow even thinner should Moore lose to Democrat Doug Jones in a special election December 12.
Trump did support moves by the national Republican Party to cut off money for Moore.
But he hasn't said whether he still backs Moore's candidacy.
Spokeswoman Sarah Huckabee Sanders, pressed repeatedly on the matter this week, would say only that Trump "thinks that the people of Alabama should make the decision on who their next senator should be."
As for the allegations against Moore, Sanders said Trump finds them "very troubling."
As for Franken, presidential adviser Kellyanne Conway told Fox News that Trump had merely "weighed in as he does on the news of the day" when jabbing at the senator.
But Trump's broadsides at Franken served as an open invitation for critics to revisit his own history of alleged sexual misconduct.
Leeds, for her part, called the president "the walking definition of hypocrisy."
Look no further than the bipartisan howl that greeted Ivanka Trump's statement this week about Moore for a demonstration of the perilous crosscurrents around Trump on the issue.
"There's a special place in hell for people who prey on children," Trump's daughter told the AP, adding that she had "no reason to doubt the victims' accounts." She did not call for Moore to leave the race.
Liberals and conservatives both pounced. Those on the left noted she had waited a week to chime in and had never given similar credence to the claims of her father's accusers.
Some on the right faulted her for buying into unproven accusations.
Liberal movie director Rob Reiner tweeted: "Ivanka believes Roy Moore's accusers. But the more than 12 women who accuse her father of sexual abuse are all liars. The difference is? ..."
The sexual assault drama is playing out as a painful sequel for Leeds and other women who came forward during the 2016 presidential campaign to accuse Trump of harassment and more - only to see him elected president anyway.
"My pain is everyday," Jill Harth, a former business associate who claimed Trump put his hands under her dress during a business dinner in 1992, tweeted in October. "No one gets it unless it happens to them. NO one!"
It's the same for those who accused former President Bill Clinton of sexual misconduct, their charges once written off as "bimbo eruptions."
"I am now 73....it never goes away," nurse Juanita Broaddrick, who accused Clinton of raping her in 1978, tweeted Friday.
Allegations of womanizing, extramarital affairs and abuse dogged Clinton over the course of his political life, culminating in his 1998 impeachment - and acquittal - over his affair with White House intern Monica Lewinsky. He also agreed to an US$850,000 settlement with Arkansas state worker Paula Jones, who had accused him of exposing himself and making indecent propositions when he was governor. The settlement included no apology or admission of guilt.
Leading feminists and Democratic-leaning groups stayed loyal to him throughout - though some are rethinking that stance now.
Even in the current charged environment, when every new allegation can produce screaming headlines, Trump may well be able to go his own way - and take a hands-off approach to Moore.
"Trump's base likes him when he's gratuitously ornery: Insulting war heroes, Gold Star families and the disabled have all been good for him, so what does he gain by strongly opining on Moore?" asks Dezenhall.
"Nothing that I can see, so as a guideline, he doesn't need to do all that much."
- AP
