How intense are feelings about John Bolton in some quarters of the U.S. Senate? Consider these snippets of conversation Tuesday with a GOP senator:

Me: "What is John Bolton up to?"

Senator: "I have no f---ing idea. This is not funny. If he has something to say, he should say it and stop trying to sell books."

Me: "It is odd that financial considerations have played a role in something like this."

Senator: "I hope he chokes on the money."

After that, I ran those sentiments by a couple of other Republican senators. They did not endorse those words, but they were clearly unhappy with President Trump's former national security adviser.

"I think we all know Bolton is no shrinking violet," said one senator in an email exchange. "If he had felt the president had stepped over a line, he would have walked right into the legal counsel office and reported. This is all about selling a book. The timing is no coincidence."

Yet another senator saw the matter as less about money than about the nature of Bolton's personality. "I assume he's motivated at least as much by ego and score-settling at his age and stage of life," the senator said via text. "Surely he doesn't need the money. But I think he needs to be right."

Not long after the senators spoke, Trump opened fire on Bolton with a three-tweet attack:

"For a guy who couldn't get approved for the Ambassador to the UN years ago, couldn't get approved for anything since, 'begged' me for a non Senate approved job, which I gave him despite many saying 'Don't do it, sir,' takes the job, mistakenly says 'Libyan Model' on TV, and many more mistakes of judgment, gets fired because frankly, if I listened to him, we would be in World War Six by now, and goes out and IMMEDIATELY writes a nasty & untrue book. All Classified National Security. Who would do this? Why didn't John Bolton complain about this 'nonsense' a long time ago, when he was very publicly terminated. He said, not that it matters, NOTHING!"

Other Republicans, meanwhile, are now attacking Bolton's credibility. They quoted President George W. Bush saying in 2008, "Let me just say from the outset that I don't consider Bolton credible." An article in Yahoo News quoted Bush administration veteran Carl Ford as calling Bolton a "kiss-up, kick-down sort of guy" who "goes out of his way to retaliate" against people who have crossed him.

Yahoo News even dredged up the case of a woman who in 2005 accused Bolton of harassing her, telling a Senate committee in 2005 that "John Bolton put me through hell."

Democrats, who in the past would have embraced all those accusations, now suggest Bolton will be a very credible witness. Republicans, who in the past would have rejected all those accusations, now suggest Bolton might not be a credible witness at all.

Some of Bolton's old friends are now his enemies, and some of his old enemies are now his friends — at least as long as he might be useful in the cause of removing Trump from office or, failing that, damaging his reelection prospects.

It is not at all clear what Bolton will do and what the Senate will want him to do. For a moment on Wednesday, the leaks of his book's contents seem to have paused. But it seems difficult to believe they will stop, especially as decision time on Bolton nears.