John Bolton knows which 4 GOP senators will vote to allow his testimony: Longtime colleague Nicolle Wallace
Composite image of Ambassador John Bolton and Sen. Mitch McConnell. Photos by Gage Skidmore.

MSNBC anchor Nicolle Wallace reported on the "tectonic plate-shifting impeachment news" after Ambassador John Bolton announced on Monday that he would be willing to testify before the U.S. Senate during President Donald Trump's impeachment trial.

Bolton, who served as Trump's National Security Advisor, was reportedly alarmed the "drug deal" with Ukraine.

That has White House aides worried, because having worked with Bolton they know he took copious notes that could bolster his testimony by proving contemporaneous documentation.

"Bolton -- either playing for U.S. national security interests or playing for the history books or both -- has, in the absence of any legal ruling forcing his testimony, examined the separation of powers questions himself and offered to testify before the Senate," Wallace explained.

The focus is now on Senate Majority Leader Mitch McConnell, who is now facing added pressure to allow witnesses to testify during the trial.

The host noted it would only take four Republican senators joining with Democrats to allow Bolton to testify and that polls show Americans overwhelmingly want to hear from witnesses.

[caption id="attachment_1577337" align="aligncenter" width="640"] MSNBC graphic of a Washington Post and ABC News poll on the question of witnesses at Trump's impeachment trial.[/caption]

Wallace worked with Bolton when the two were senior officials in the George W. Bush administration.

"Knowing Bolton for the better parted of two decades, it's a decent bet he just might know where four votes to hear from the first-hand witness might be hiding," Wallace revealed.