IMAGINE THERE'S NO WITNESS TESTIMONY. IT'S EASY IF YOU TRY.

We now know that John Bolton's book will be published on March 17. When major political books are embargoed -- which means the contents aren't released to reviewers in advance -- it's now standard practice for the books to be mysteriously acquired by The Washington Post, The New York Times, The Wall Street Journal, and/or CNN so that full reviews and news stories can appear about a week before the publication date. But that would be March 10 -- long after the impeachment trial is likely to end if it stays on its current course. So the leak of a rough version of the book had to happen now in order for it to have some possible influence on the trial.

Therefore, we have this Maggie Haberman/Michael Schmidt report in the Times:

President Trump told his national security adviser in August that he wanted to continue freezing $391 million in security assistance to Ukraine until officials there helped with investigations into Democrats including the Bidens, according to an unpublished manuscript by the former adviser, John R. Bolton.

The president’s statement as described by Mr. Bolton could undercut a key element of his impeachment defense: that the holdup in aid was separate from Mr. Trump’s requests that Ukraine announce investigations into his perceived enemies, including former Vice President Joseph R. Biden Jr. and his son Hunter Biden, who had worked for a Ukrainian energy firm while his father was in office.

But will this matter? The folks who write Politico's Playbook seem to think so.

MAGGIE and MIKE’S story is as bad as can be for TRUMP. BOLTON is now contradicting the president’s claim that he did not tie the aid to investigating JOE BIDEN, and he is a direct eyewitness. It comes at the absolute worst time for this White House: as the Senate is days away from deciding whether to call witnesses in the impeachment trial.

... AS OF LATE SUNDAY, our GOP sources said they could not predict what was going to happen now with witnesses, and the Republican Conference lunch today will be key in determining the state of play. In other words, these top-level sources were allowing that things may have changed. We have yet to see if Republicans will brush off this new development, or whether it will push enough of them to vote for witnesses.

... HERE’S THE DILEMMA FOR REPUBLICANS NOW: If you’re one of the Republicans who were already uncomfortable with this president, how do you vote to not call Bolton after seeing this?

Don't worry -- they'll find a way.

As the Times story notes, "a week into the trial, most lawmakers say the chances of 51 senators agreeing to call witnesses are dwindling, not growing." As the Times reported on Friday:

Senator Lamar Alexander, Republican of Tennessee, who had signaled potential interest in considering new evidence, ... did not sound eager to push the proceeding into the unknown.

“As the House managers have said many times, they’ve presented us with a mountain of overwhelming evidence, so we have a lot to consider already,” he told reporters.

Another possible vote for witnesses, Senator Lisa Murkowski of Alaska, also sounded reluctant on Thursday, citing an argument being made by the president’s legal team and her more conservative colleagues against extending the trial.

“The House made a decision that they didn’t want to slow things down by having to go through courts,” Ms. Murkowski said. “And yet now they’re basically saying ‘You guys — the Senate — got to go through the courts. We didn’t, but we need you to.’”

And on Friday, when Representative Adam B. Schiff, the lead House manager, referred to a news report that Republican senators had been warned that their heads would be “on a pike” if they strayed from Mr. Trump, Ms. Collins and Ms. Murkowski were among those visibly outraged.

I've been telling you for days that Senate Republicans will blame phony offenses by Democrats for their decision to end the trial quickly. On CNN Friday, Democratic senator Sheldon Whitehouse of Rhode Island gave this approach a name:

Sen Whitehouse: Republicans are "desperate to find an outrage off-ramp" pic.twitter.com/m4EfZmQJfh

— TPM Livewire (@TPMLiveWire) January 25, 2020

SEN. SHELDON WHITEHOUSE (D-RI): ... I think that if you are a Republican, and you're looking at a really damning case, that you have no counter to, and where you're sitting on lockers full of evidence, and not allowing it into the trial, you are desperate to find an outrage off-ramp.

And they will find something outrageous in parts per billion in order to seize the outrage off-ramp and get away from the damning case that has been made on the substance.

Senate Republicans will use the outrage off-ramp to dismiss the case for Bolton's testimony. And if they don't think that will work, maybe a few of them will concede that testimony from Bolton would be a good idea -- but then the question of his testimony will get mixed up in the fight for Republican witnesses:

If the Senate decides to consider new impeachment trial witnesses and documents next week, Sen. Josh Hawley plans to try and force votes on everyone from Adam Schiff to Joe Biden.

The Missouri Republican is preparing to file subpoena requests for witnesses and documents that Democrats and Republicans alike won't want to vote on. Hawley's strategy harmonizes with plans from GOP Sens. Ted Cruz of Texas and Rand Paul of Kentucky to force votes to hear from Hunter Biden....

If the witness vote succeeds, Hawley aims to force votes on subpoenas for House Intelligence Chairman Schiff (D-Calif.), Vice President Biden, Hunter Biden, Intelligence Community Inspector General Michael Atkinson, the still-unnamed whistleblower who reported Trump's July call with the Ukrainian president and a reported acquaintance of the whistleblower's.

Although Joe Biden rejected the notion last week, I think Democrats would swap a Biden for Bolton. But an aggressive Republican move to subpoena a Trump wish list of witnesses will lead to a protracted fight, after which Republicans -- who are much better than Democrats at message discipline -- will say that no agreement could be reached because Democrats are afraid to hear witnesses. End of witness fight; end of trial. Bolton's book, published a month after the trial, will have about the same impact as the release of the Mueller report a month after the William Barr spin.

So don't get your hopes up. There won't be witnesses.

*****

I should also add that Republicans will insist that the Trump defense was so devastatingly effective that witnesses can't possibly contradict it:

It took less than 2 hours for the White House Counsel to completely shred and eviscerate Adam Schiff’s case.

The President’s legal team focused on the indisputable facts and effectively showed the American people what Adam Schiff has been hiding from them - the TRUTH.

— Elise Stefanik (@EliseStefanik) January 25, 2020

This isn't true, but Republicans know that most Americans aren't watching the trial and have no idea. So why not say this?