Ross Douthat(CREDIT: Josh Haner/The New York Times)

In 2014, Matt Bai published a book called “All the Truth Is Out,” a history of Gary Hart’s scandal-driven downfall that doubled as a lament for political journalism’s surrender to the lure of tabloid culture.

Bai’s book title was a little bit misleading. Even today, we don’t get all the truth about the sex lives of the powerful and famous. We get more of it than people got in the 1960s, but it still often comes in fragments, glimpses, rumor and conjecture.

There’s a certain randomness to when a scandal actually breaks big. To take a nonpolitical example, Bill Cosby’s sexual exploitations were kinda-sorta in the public record for years and years, but they were a footnote in profiles and biographies until Hannibal Buress started talking about Cosby-the-rapist in his comedy routines. Then suddenly, it was a story, a cascade of stories, and the whole truth or something close was out.

Similarly, in the political realm, The National Enquirer first published John Edwards-Rielle Hunter stories in October 2007. But Edwards was able to make his way through an entire primary campaign before the mainstream media finally, reluctantly, started reporting on his love child.

Which brings us to Bill Clinton, whose old scandals are once more in the news — because Donald Trump is talking about them, because Juanita Broaddrick took to Twitter to reassert her claim that Clinton raped her in 1978, and because today’s liberal deference toward rape victims makes an uneasy fit with how the Clinton camp dealt with accusations from Broaddrick, Kathleen Willey and Paula Jones in the 1990s.

This has produced a lot of discussion about whether the former president’s sexual past is “fair game” during his wife’s 2016 campaign. But that question tends to assume that there’s some consensus about the former president’s sexual past. It assumes that all the truth is out.

In reality, though, the narrative around Clinton’s sexual past is highly unstable, with several variations that have a plausible claim on being true.

There’s the official Clintonite narrative, in which the former president strayed with Gennifer Flowers and Monica Lewinsky, was forgiven by his wife and daughter, and deserves to have his repentance respected.

Then there’s the narrative that I suspect most Americans believe, in which the former president was much more of a tomcat in Arkansas, and probably has tomcatted occasionally in his post-presidency — but always consensually, and lately in ways that have minimized exposure or embarrassment.

If either of these narratives is true, then Clinton’s sex life will be a nonissue in 2016. If an adulterer, even a frequent adulterer, is all he is, then an America that didn’t want him impeached in the 1990s isn’t going to object to having him as the first gentleman today.

But suppose you believe the Broaddrick story. Liberals dismissed it during the impeachment days, but if you read the summary of the case from the (mostly liberal) Dylan Matthews at the (mostly liberal) website Vox, this dismissal looks unfair. There’s an inescapable he-said/she-said dynamic, but one need not be a “believe all rape allegations” absolutist to find her claim persuasive.

If she’s telling the truth, then Clinton’s sexual past becomes something more predatory. The slippage between a powerful man’s dalliances and straightforward predation is something that could happen just once. But looked at in the light of a credible rape allegation, there are all sorts of Clinton stories — the Willey and Jones cases, the rumors collected by Jones’ lawyers, the old tales of state troopers being used as procurers, the 2002 globe-trotting on the jet of a billionaire who’s also a convicted statutory rapist — that could suggest a darker pattern, tending toward the Cosby-esque.

The truth about Bill Clinton’s past, then, is that we don’t actually know the truth. And even in our tabloid-driven age, it’s quite possible that we simply never will.

But if the question is, “Does Bill’s past matter for Hillary’s campaign?” the answer depends less on what we know right now than on what might be waiting to come out.

— Ross Douthat is a columnist for The New York Times.