BYRON YORK: Trump dossier mystery deepens.

On Wednesday, not long after I posted the story, “Republicans skeptical about origin of Trump dossier,” I got a note from a friend who had been thinking about the claim that a wealthy GOP donor started the infamous Trump dossier.

I had reported that the Republican operatives who ran against Donald Trump — the managers of the Ted Cruz, Marco Rubio, Jeb Bush, and John Kasich campaigns — had not only not heard of any GOP-funded oppo project but did not believe one existed. Neither did some of the NeverTrump activists working outside the campaigns to try to stop the GOP front-runner.

“The reason it is not at all believable that a Republican was behind it is, nobody used [any information] from it,” Rubio campaign manager Terry Sullivan told me. “Everybody was pretty damn desperate at the end. If someone had a kitchen sink, they would have thrown it.”

My friend thought there might be some semantics involved. “The phrase ‘wealthy Republican donor’ doesn’t necessarily have to denote a Republican,” he wrote in an email exchange. “It could refer to a Democrat who has also made occasional donations to Republicans, especially if the source of the info is trying to mislead without technically lying.”

Yes, it could. And in so many investigations, misleading-without-technically-lying is the Washington way. So perhaps the dossier origin story fits in that category.

Meanwhile, staffers for the Senate Judiciary Committee are going over hours of testimony given Tuesday by the man who made the dossier happen, Fusion GPS founder Glenn Simpson. Investigators are waiting for a transcript, and committee chairman Sen. Chuck Grassley said at a town hall meeting in Iowa Wednesday that he’ll hold a committee vote on releasing the transcript publicly (and that he’ll vote in favor of release).

But the fact is, on the question many in the public want answered — who paid for the dossier? — Simpson and his lawyers have been refusing to answer for quite a while, and after the interview Tuesday, Simpson lawyer Josh Levy said that Simpson “kept the identities of Fusion GPS’s clients confidential.”

Well, that suggests to me that it wasn’t a Republican. People seldom go that far to protect their secrets.