But as much as this moment has hung like an ugly spectre over an already astonishingly nasty presidential campaign, the risks for Trump in bringing up Bill Clinton's behaviour have only increased as the race has continued.
In scrambling to respond to the video, the Trump campaign has put the final piece of a trap for its own candidate in place. No matter where Trump turns in trying to attack Bill and Hillary Clinton, a snare can tighten around him, too.
First, though it's astonishing that it needs saying, Hillary and Bill Clinton are actually distinct human beings.
Say Trump wants to suggest that Hillary Clinton bears some sort of auxiliary responsibility for her husband's sexual behaviour.
He's still asking voters to decide between someone who is married to a person who behaves badly, and a person who has acknowledged that it was him on that videotape, describing a strategy for assaulting and groping women using the power of his celebrity. That may not be an appealing choice, but it's still not one where Trump can claim any sort of moral high ground.
Next, if Trump is going to suggest that Bill Clinton is a rapist, rather than merely an adulterer, he opens the door to discussions of his own behaviour. Trump has been sued for alleged sexual harassment and sexual assault by Jill Harth, former business partner.
I suppose Trump might be able to argue that he got a better deal in resolving that suit than Bill Clinton did in his settlement with Paula Jones, who accused him of sexual harassment; Clinton paid her US$850,000.
As Nicholas Kristof reports, Trump made withdrawing Harth's harassment suit a condition for resolving a contract dispute with Harth and George Houraney, and paid the couple "somewhat more than US$100,000".
Trump has already defended so many other things, including avoiding paying taxes and cheering on the Great Recession, as proof of his good business sense that adding this to the list would hardly constitute a new low.
Maybe Trump will try to paint Hillary Clinton as an enabler for staying with her husband, but then I'm not sure what that makes his own wife.
At the weekend, Melania Trump released a statement saying "I hope people will accept his apology, as I have, and focus on the important issues facing our nation and the world".
By the standards Trump has set for Clinton, Melania Trump should be packing her bags and joining a picket line outside of Trump Tower warning women the world over about her husband's conduct, not using her own forgiveness to try to compel ours.
And if Trump tries to suggest that Clinton actively worked to discredit the women who said they had consensual sex with Bill Clinton, or to intimidate Broaddrick, there's trouble there, too.
In the tape published on Saturday NZT, Trump discussed his attempts to seduce Nancy O'Dell, then a host of Access Hollywood. As he acknowledged, they failed. Trump later tried to have her fired from the Miss USA pageant. The stated reason Trump wanted her gone? "He doesn't like the way pregnant women look," per TMZ.
To reiterate: If Donald Trump wasn't retaliating against Nancy O'Dell for refusing to have sex with him, the better alternative narrative is that he thinks pregnant women are unbearably, unemployably hideous.
At the beginning of the race, running for president probably seemed like a dream come true to someone as narcissistic as Trump.
By now, it would be a nightmare if Trump had the decency to recognise it. Wherever he turns, whatever charges he tries to level, his reflection is staring back at him.
