Ted Cruz is getting credit for floating this idea to Cocaine Mitch but a one-for-one deal on witnesses between the two sides was unavoidable. Or at least it was once John Bolton cleared his throat and told the world he’d testify if subpoenaed. Until that moment I think McConnell was still holding out hope of having a trial with no witnesses. House Dems would present their case based on the evidence gathered during Schiff’s hearings, then Trump’s lawyers would present a defense, and then the Senate would hold a vote on whether to call witnesses. Result: Nope, no witnesses. They’re done. Time to issue a verdict. The Susan Collins contingent would have gone along with that, I suspect, on grounds that there was no way to expeditiously compel Bolton and other Trump aides like Mick Mulvaney to testify while the president was asserting “absolute immunity.”

But everything changed once Bolton said he’d ignore “absolute immunity” and show up. Suddenly the Collins crowd faced real pressure to call him. If their goal in all this is to show swing voters that they did their jobs diligently as jurors before voting “not guilty” then declining to call a witness as significant as Bolton after he’d promised to testify would have made that very hard. They’d have to call him, to McConnell’s chagrin.

So now he’s embracing the back-up plan, ensuring that House Dems and the president get the same number of witnesses. That will help Collins et al. convince voters on both sides that they were scrupulously fair. And it might discourage Dems from demanding to hear from the likes of Lev Parnas, knowing that that would mean granting Trump a second witness too.

During the 30-minute session, Cruz pitched McConnell on the idea of witness reciprocity — if Democrats want to hear from former Trump national security adviser John Bolton on the Ukraine scandal, then Republicans get to hear from Hunter Biden. McConnell was open to that message, said a source familiar with the discussion. Cruz and Sen. Rand Paul (R-Ky.) later raised the strategy to the broader Senate Republican Conference…

“We’ll be dealing with the witness issue at the appropriate time into the trial,” McConnell told reporters [later]. “And I think it’s certainly appropriate to point out that both sides would want to call witnesses if they wanted to hear from them. So if you get to that issue, I can’t imagine that only the witnesses our Democratic colleagues want to call will be called.”

McConnell’s dream here is deterrence. He wants Pelosi and Schumer to digest the idea of “witness reciprocity” and decide that it’s more important to stop Hunter Biden from testifying than to force Bolton to do so. If that happened, with Dems refusing to play ball, Collins et al. would suddenly have political cover to say, “To hell with it, we’re not calling any witnesses then. If the Democrats aren’t interested in getting to the full truth here then there’s no reason to proceed further. Trial over.”

But Bolton’s announcement that he’s willing to testify has put Democratic leaders in a jam too. Before he said that, I think Dem leaders would have carefully considered whether the risk to Joe Biden next fall in what Hunter might say (or at least might be accused of on national television) outweighed the value of forcing Bolton to take the stand. Remember, the trial’s outcome is assured no matter what Bolton claims. If Dems “win” now by getting him to testify and the Senate acquits Trump anyway, and meanwhile “witness reciprocity” forces Hunter Biden before a gigantic audience to feed suspicions about Burisma and possible corruption by his father, Joe Biden could end up more damaged by this process than Trump is. The election could depend on it. But, thanks to Bolton, the question is now academic: Lefties are salivating at the thought of having him testify at long last and Pelosi and Schumer can’t deny them that gratification. They’re going to have to call him — even if it means calling Hunter Biden too.

Anyway, two questions. One: If Dems succeed in calling *two* witnesses, say, Bolton and Lev Parnas (which is unlikely), who are the two who get called by Trump? Hunter is one, obviously. But who’s the other?

I don’t think the Collins crew will go for any of those other witnesses. The whistleblower is old news by now and Senate Republicans don’t want to start playing games with the other chamber by putting House Dems on the stand. Otherwise Senate GOPers will soon be hauled into House hearings on various matters. Calling Joe Biden would make sense in the context of a defense focused on Burisma but McConnell would be deathly afraid of Biden turning his testimony into an opportunity to grandstand against Trump and to forcefully assert his own innocence. Remember, Cocaine Mitch wants as little risk from this trial as possible. Putting the would-be Democratic nominee on television knowing that a good performance might help propel him not just to the nomination but to the presidency would be the highest possible risk.

They’re going to need to find a second witness. Someone from Ukraine, maybe? Does Trump dare roll the dice on the credibility of a Ukrainian official?

Question two: Are we sure there are four Republicans in the Collins crew who are willing to join Schumer in calling witnesses? Four is what he needs to get to a majority of 51 and he seems likely to get Collins, Murkowski, and Romney. But what about Cory Gardner, the presumptive fourth vote? The Times notes that he’s caught in a political vise:

“This is Cory’s problem, or challenge: There’s a very restless Republican base in Colorado and Cory cannot afford to alienate that base because he cannot afford any defections from the base in a general election,” said Richard Wadhams, a Republican strategist in Colorado who is close to Mr. Gardner.

“He’s in a very vulnerable position right now in the Senate election,” Mr. Wadhams added, “but believe me, it is much more dangerous for him to appear not to be supporting Trump than it is to be supporting McConnell and the president in Colorado.”

Gardner’s ace in the hole in disappointing the GOP base by agreeing to call witnesses during the trial is the fact that he’ll surely atone in the end by voting for acquittal. Not only that but “witness reciprocity” gives him an opportunity to gratify MAGA fans during the procedural phase of the trial by handing Trump as many witnesses as Dems get. I think he’ll be the fourth vote. And even if he isn’t, it’s possible that Schumer only needs three votes, not four, to call witnesses. Presumably any 50/50 split on calling someone would be resolved by John Roberts, who I assume would lean in favor of calling obviously relevant players like Bolton in the name of gathering more facts. That’s the best reason for Gardner to consider voting against calling Bolton, in fact — Roberts will probably bail him out, in which case Gardner can go home and tell Republicans that he stuck with Trump the whole way and tell Democrats that the trial was fair because, after all, they heard from John Bolton, didn’t they?

Here’s Ted Cruz yesterday on Fox talking about witness reciprocity and how the trial is likely to play out.