“The reporting on John Bolton strengthens the case for witnesses. It has prompted a lot of conversations among my colleagues,” Sen. Susan Collins (R-Maine) told VICE News.

WASHINGTON John Boltons bombshell may have blown a hole in the GOP plan to end Trumps impeachment trial without any witnesses.
The Republicans most likely to decide if Trumps trial will include new witnesses said Monday that Boltons new claims make it more important that the Senate hear from him under oath. And given how explosive Boltons claims are, they may not be alone.
The reporting on John Bolton strengthens the case for witnesses. It has prompted a lot of conversations among my colleagues, Sen. Susan Collins (R-Maine) told VICE News.
Bolton reportedly writes in his upcoming book that Trump told him directly that he had suspended $391 million in military aid in order to pressure Ukraine, a claim that knocks down the central defense from Trumps team: That no ones said Trump directly ordered the hold on aid for selfish political reasons.
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Democrats have pushed for Bolton to testify since the beginning of the trial, and hes said hed be willing to appear under subpoena. Democrats would need four Republicans to defect, and keep all of its votes to compel witnesses. That didnt look likely to happen until now.
House Intelligence Committee Chairman Adam Schiff (D-Calif.), the Houses lead impeachment manager, said the news of Boltons direct conversation with President Trump makes it all the more clear why you can’t have a trial, a meaningful trial, without witnesses.
Boltons public testimony could be crucial. Trumps defense has centered on the claim that no one has directly testified that they were ordered by Trump to withhold aid from Ukraine until the countrys leader agreed to announce an investigation into Joe Biden, an argument his lawyers returned to on Monday.
Thats already not entirely true multiple people testified that Trump made these demands crystal clear to U.S. Ambassador to the European Union Gordon Sondland, and that Sondland relayed those conversations in real time.
But if Trumps former national security adviser comes to the Senate and swears under oath that the president did indeed condition military aid on political favors, that would knock down any remaining question of Trumps knowledge of the plot.
I think it’s increasingly clear that what John Bolton would have to say would be important for those of us who are asked to render impartial justice.
I think it’s increasingly clear that what John Bolton would have to say would be important for those of us who are asked to render impartial justice, Sen. Mitt Romney (R-Utah) told VICE News on Monday at the Capitol.
Earlier, Romney told reporters it was increasingly likely that other Republicans will join those of us who think we should hear from John Bolton.
Just days ago, it appeared that too few Republican senators would be willing to buck their party on allowing new witnesses. Four Republicans need to break with Trump, and only had signaled they were leaning towards doing that: Romney, Collins and Sen. Lisa Murkowski (R-Alaska).
I said before I was curious about what Ambassador Bolton might have to say. Im still curious, Murkowski said Monday.
With those three onboard, one more GOP senator would need to break with their party for there to be the 51 Senate votes needed to call new witnesses. The most likely to do so was keeping his cards close to the vest.
Ive worked with my colleagues to make sure we have a chance after weve heard the arguments, after weve asked our questions, to decide if we need additional evidence, and Ill decide then at that time, Sen. Lamar Alexander (R-Tenn.) told reporters as he walked to to the Senate floor Monday afternoon for the resumption of the impeachment trial.
Alexander tops the list of Republicans who might break with Trump if hes not the entirety of the list by himself. A moderate with a long independent streak whos retiring at the end of 2020, hes by far the most likely to split with Trump. Others to keep an eye on include moderate Sen. Rob Portman (R-Ohio) and Sen. Cory Gardner (R-Colo.), whos up for reelection in a blue-leaning state this fall, but both appear less likely to buck their party.
The Bolton news is unlikely to dramatically reshape how Republican senators handle the remainder of the impeachment trial. Most will still vote against removing Trump from office, and its still not even clear if four will split from their party to allow the Senate to call witnesses like Bolton.
But the latest news ramps up pressure on both the handful of GOP moderates who are taking impeachment seriously and on the few Republicans facing tough reelection fights next fall, like Gardner, Collins and Sens. Martha McSally (R-Ariz.) and Thom Tillis (R-N.C.).
Its taken an already-hot topic and added some fuel to the fire, said Sen. Mike Braun (R-Ind.).
Cover: Sen. Mitt Romney (R-UT) talks to reporters before heading into the weekly Senate Republican policy luncheon at the U.S. Capitol January 21, 2020 in Washington, DC. Senators will vote Tuesday on the rules for President Donald Trump’s impeachment trial, which is expected to last three to five weeks. (Photo by Chip Somodevilla/Getty Images)