Reeeeeeeally shady for Engel, the chairman of the Foreign Affairs Committee, to sit on this for four months. If it’s worth revealing when the Senate is 48 hours away from deciding the momentous question of whether to call Bolton as a witness, why wasn’t it worth revealing a month ago? Or the day after the call happened?

Sure seems like it’s been carefully timed to maximize the political pressure on Susan Collins, Mitt Romney, Lisa Murkowski, and (maybe but probably not) Lamar Alexander. After all, the more Bolton potentially has to reveal, the more compelling the argument becomes for deposing him. Was his knowledge of the Ukraine matter limited to Trump’s intentions about a quid pro quo or did he know more — maybe up to and including the details of Giuliani’s scheme to get Yovanovitch recalled so that she wouldn’t interfere with the pressure on Zelensky over Burisma?

Does Bolton also happen to know if Yovanovitch’s boss, Mike Pompeo, was part of that scheme?

Engel’s claim could be a lie, of course, a Democratic dirty trick. But as I write this at 2 p.m. ET the taciturn John Bolton hasn’t said anything to dispute it.

Note the date of their alleged call. An NBC reporter pointed out on Twitter that Pelosi finally announced the formal impeachment inquiry just one day later, on September 24. Did Engel tell her what Bolton had told him, convincing her that it was time to move?

The retort to Engel will be that Trump has full constitutional authority to remove an ambassador. That’s true, but his reason for removing her might inform the larger question of whether his motive in the quid pro quo was corrupt or not. A president has plenary constitutional power to pardon federal offenders, but if, for instance, he pardoned a thief in exchange for that thief handing over his loot to the president, he could be impeached for the corruption inherent in such an abuse of power. The obvious question for Bolton would be, “What makes you think ‘something improper’ motivated Yovanovitch’s ouster?” We know for a fact that Lev Parnas was whispering to Trump that she was insubordinate a full year before she was removed. Insubordination is a legit reason to dismiss an employee. What leads Bolton to believe there was more to it?

Engel also has a defense (if not a persuasive one) on the convenient timing of his revelation. Trump raised the issue last night of why Bolton didn’t speak out about the Ukraine saga sooner. It’s suspicious that he waited until he had a book to sell to say anything about alleged wrongdoing, no?

Bolton did speak out not long after he left the White House, Engel’s claiming. He didn’t coincidentally develop concerns about the Ukraine matter only recently, when it might benefit him financially to do so. Nor is Engel the first person to whom Bolton allegedly complained about the Ukraine business. Remember Fiona Hill’s testimony before the House in October:

Mr. Bolton got into a tense exchange on July 10 with Gordon D. Sondland, the Trump donor turned ambassador to the European Union, who was working with Rudolph W. Giuliani, the president’s personal lawyer, to press Ukraine to investigate Democrats, according to three people who heard the testimony.

The aide, Fiona Hill, testified that Mr. Bolton told her to notify the chief lawyer for the National Security Council about a rogue effort by Mr. Sondland, Mr. Giuliani and Mick Mulvaney, the acting White House chief of staff, according to the people familiar with the testimony.

“I am not part of whatever drug deal Sondland and Mulvaney are cooking up,” Mr. Bolton, a Yale-trained lawyer, told Ms. Hill to tell White House lawyers, according to two people at the deposition. (Another person in the room initially said Mr. Bolton referred to Mr. Giuliani and Mr. Mulvaney, but two others said he cited Mr. Sondland.)

If you believe Hill, Bolton was instructing people to alert White House counsel about Ukraine shenanigans months before the Ukraine deal was publicly known. The proper question isn’t why he took so long to object to it. The proper question is why, having objected to it so long ago, has he been so tight-lipped in public. Odds are high as I write this that the impeachment trial will end this weekend with no witnesses being called, all because Bolton has resolutely refused to tell a single reporter what he knows.

Two questions to ponder while we wait to see if this week’s excruciating drama will finally convince him to speak. One: Did Engel release today’s statement with Bolton’s approval? I pointed out yesterday that Bolton has been doing everything he can to signal to the Senate that they should subpoena him, first declaring at the beginning of the month that he’ll testify if called and then — maybe — leaking that bit from his book to the Times about what Trump knew about a quid pro quo. It would stand to reason that Bolton might have nudged Engel to reveal their call, just to turn up the heat further on Susan Collins et al.

Two: If Engel and Pelosi knew as far back as September that Bolton had information about “improper” conduct in the Ukraine matter, why the hell didn’t they subpoena him? It’s one thing for them to say that they didn’t want to delay impeachment for months to fight a court battle over executive privilege when they didn’t know if Bolton would have anything juicy to tell them. But they did know, according to Engel. They had every reason to believe that subpoena would pay off handsomely. Why didn’t they go after him, particularly given his willingness to tip off Democrats like Engel? It’s inexplicable.