There’s nothing Democrats could do about that. The only prayer they had was to have Bolton and/or Mulvaney signal they’re willing to testify, which would spare Senate Republicans from a long court fight to get them to appear, and there seemed to be zero chance of that happening. Mulvaney is still the chief of staff, after all, beholden to the president’s wishes. And although Bolton’s now a somewhat disgruntled former aide, he’s kept his head down during the impeachment saga. No Democrat-friendly soundbites from him about Trump’s guilt, no inkling that he had any intention of cooperating. Impeachment was going to have to play out without any damning testimony from the president’s inner circle, making acquittal easy for Senate Republicans and a speedy, risk-free trial easy for McConnell.

And now here we are, on the first day back from the holiday break, and the table that was being carefully set has been flipped.

During the present impeachment controversy, I have tried to meet my obligations both as a citizen and as former National Security Advisor. My colleague, Dr. Charles Kupperman, faced with a House committee subpoena on the one hand, and a Presidential directive not to testify on the other, sought final resolution of this Constitutional conflict from the Federal judiciary. After my counsel informed the House committee that I too would seek judicial resolution of these Constitutional issues, the committee chose not to subpoena me. Nevertheless, I publicly resolved to be guided by the outcome of Dr. Kupperman’s case…

The House has concluded its Constitutional responsibility by adopting Articles of Impeachment related to the Ukraine matter. It now falls to the Senate to fulfill its Constitutional obligation to try impeachments, and it does not appear possible that a final judicial resolution of the still-unanswered Constitutional questions can be obtained before the Senate acts.

Accordingly, since my testimony is once again at issue, I have had to resolve the serious competing issues as best I could, based on careful consideration and study. I have concluded that, if the Senate issues a subpoena for my testimony, I am prepared to testify.

What does McConnell do now? Bolton obviously has material information about the Ukraine matter — maybe incriminating, maybe exculpatory. There might not be a delay, it seems, if the Senate calls him to testify. So what’s the excuse for not calling him? Right, sure, Republicans could double down on the argument that the House should have called him first, but that’s a hard sell as a justification for refusing to call him at all. The trial, after all, is a factfinding exercise and Bolton knows pertinent facts; refusing to call him without a procedural excuse to avoid doing so would be tantamount to willful blindness about the defendant’s guilt or innocence.

We don’t even need to ask what McConnell will do, actually. The majority leader doesn’t have the same authority over an impeachment trial that he has over regular Senate business. What we need to ask is what Susan Collins, Lisa Murkowski, Mitt Romney, Martha McSally, and Cory Gardner will do. Collectively they can get Schumer to 51 votes (52, actually) in favor of subpoenaing Bolton. Collins and Gardner in particular want to appear as though they’re taking the trial deadly seriously, as they’re up for reelection next fall and don’t want to antagonize anti-Trump voters back home any more than is necessary by voting for acquittal. Letting Bolton testify lets them tell those voters that they gave Democrats every chance to prove their case against the president, which may appease some of them, whereas blocking Bolton on flimsy grounds risks making their acquittal vote look like a sham. And they may worry about what Bolton might say about Trump’s guilt later, in a book or interview, if he doesn’t get to say it under oath. An acquittal vote would be a political headache long-term if Bolton turns around later and says, “Yeah, Trump was guilty as sin, they really should have called me.”

There’s another complication. If Bolton is called, Trump will insist on calling new defense witnesses to make things fair. If Collins et al. are willing to hand Democrats extra ammo in the form of this subpoena, they’ll need to be prepared to hand some to the president by calling Hunter Biden or the whistleblower or whoever. That’s McConnell’s nightmare scenario — a trial that effectively ends up as two separate trials for Trump and the Bidens, and which could steer in unpredictable directions.

The weirdest part of all this is the timing. You would think Bolton would feel less disgruntled towards Trump after he liquidated Iran’s arch-terrorist Soleimani and not want to contribute to the distraction of impeachment as the risk of war rises. Nope. Here’s one of the most hawkish Republicans in the natsec establishment tossing a grenade into Trump’s and the GOP’s pre-impeachment planning.

Democrats are celebrating:

In light of Bolton willingness to testify, Dems argue that Pelosi strategy to withhold articles has been vindicated. “We would not have this development absent the Speaker's hold," a senior Democratic aide said. "Another proof point that indicates the value of her strategy."

— Manu Raju (@mkraju) January 6, 2020

Was “impeach and delay” … coordinated with Bolton? Presumably not, but it seems almost too good to be true for Pelosi that she engaged in this cockamamie strategy aimed at pressuring McConnell to call more witnesses, appeared to have no leverage whatsoever, and suddenly the star witness is proclaiming he has a duty to testify if called by the Senate on the first day back to business for official Washington.

Senior Democrats “predicted” a few days ago to WaPo that Pelosi would send over the articles of impeachment to the Senate “in the coming days.” Is that still true after Bolton’s announcement? What if Schiff decides to subpoena Bolton? In his statement today he says that “The House has concluded its Constitutional responsibility by adopting Articles of Impeachment related to the Ukraine matter,” but that’s a matter of dispute. Some lawyers claim that Trump hasn’t been impeached until the articles are formally delivered to the Senate. Schiff could fight to compel Bolton’s testimony. Although … why would he? Now that Bolton’s joined the Democratic effort to pressure McConnell into allowing witnesses, why not keep the heat on the Senate? If they can maneuver a majority of that Republican-run chamber into forcing Bolton’s testimony with votes from the Collins faction, even better for them.

Question for legal eagles: Can Trump still block Bolton from testifying on executive privilege grounds? My read on his statement (“it does not appear possible that a final judicial resolution of the still-unanswered Constitutional questions can be obtained before the Senate acts”) is that he’s prepared to testify at this point without waiting for a ruling on that, i.e. that he’s issued his own ruling on the matter. Even if Trump can block him, though, the politics of gagging a material witness who’s willing to testify are obviously worse than gagging a witness who’s neutral or reluctant. Dems will attach an asterisk to Trump’s acquittal no matter what, but having Bolton waiting outside the Senate door, willing to tell the country what happened but silenced by the president, will cast more suspicion on the verdict than if Bolton had kept quiet about his willingness to testify. Sheesh. What a fiasco.

Exit quotation: Happy new year, Mitch.

Former White House national security adviser John Bolton left a message with Senate Majority Leader Mitch McConnell before he put out this statement, in order to give him a heads up that it was coming, a source familiar tells CNN. @kylieatwood

— Shimon Prokupecz (@ShimonPro) January 6, 2020