That places Trump much closer to actual wrongdoing than at any other point in the Russia and related investigations,
"That's potentially very bad news for Trump, because if he knew about the payments in advance or even agreed to them later, he's looking at liability as a conspirator for what is now a proven crime," said former Justice Department aide Harry Litman.
Cohen's deal does not include an agreement to cooperate with prosecutors, as we might have expected. But in making the plea, he has apparently implicated Trump in the campaign-finance violation.
Cohen told prosecutors he made the payment at the direction of an unnamed "candidate," which it seems obvious would have to be Trump.
And that means there could be plenty more to play out and this could get hairy for Trump.
"I do think a plea to paying the women moves the overall case forward in the sense that if campaign money was used to make the payments, anyone (including, in theory, then-candidate Trump) involved in that is guilty of a campaign fraud," former federal prosecutor Patrick Cotter said. "Thus, more potential witnesses and targets will result from Cohen's plea."
Other members of Trump's team - Michael Flynn, Rick Gates and George Papadopoulos - have pleaded guilty to making false statements in exchange for cooperating with prosecutors.
Former Trump campaign chairman Paul Manafort has been found guilty of eight counts in the first of two trials involving offences in his private consulting business that predated the 2016 campaign.
None of their actions during the 2016 campaign have been exonerated - and prosecutors often keep details of such investigations under wraps for as long as possible - but it remained true, before today, that neither Special Counsel Robert Mueller nor anybody else had charged with a crime or obtained a guilty plea involving a Trump aide and the 2016 campaign.
The question about whether Cohen would cooperate with prosecutors was the big one here, but it seems almost moot now.
He has already provided key evidence, and now he has rather clearly suggested, via his plea, that Trump was involved.
And Cohen has certainly previewed a willingness to do that, even publicly revealing a tape of a conversation he had with Trump about buying the rights to the story of one of Trump's accusers, former Playboy Playmate Karen McDougal.
We have crossed a new threshold in this whole matter.
