LIVE: Senate reconvenes for Trump's impeachment trial after key GOP senator announces she will vote against calling new witnesses

Andrew Harnik/AP

John Bolton

• The Senate reconvened Friday to debate whether to call additional witnesses forward in President Donald Trump's impeachment trial.
• House impeachment managers have been pushing hard to call new witnesses, like former national security adviser John Bolton, who could share firsthand knowledge of Trump's pressure campaign in Ukraine that hasn't yet come to light.
• Friday's proceedings come after The New York Times reported on yet another bombshell claim from Bolton's upcoming book, in which Bolton says Trump personally directed him to pressure Ukraine to cave to his political demands.
• Shortly before the trial, a key Republican senator, Lisa Murkowski, announced she will vote against calling new witnesses, dealing a final blow to the push to call witnesses.
• Scroll down to watch the trial and follow Insider's live coverage.
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The Senate reconvened on Friday to debate whether to call new witnesses forward in President Donald Trump's impeachment trial. After the debate, there will be a vote on witnesses and bringing forward new evidence, but it's unclear how long Friday's session will last and how long the debate will be.

Friday's proceedings also come after The New York Times reported on another bombshell claim from former national security adviser John Bolton's upcoming book, in which Bolton claims Trump personally asked him to help pressure Ukraine to cave to his personal demands.

The House of Representatives impeached Trump last month for abuse of power and obstruction of Congress. The two articles of impeachment relate to the president's efforts to strong-arm Ukraine to deliver politically motivated investigations targeting his rivals.

While doing so, Trump withheld $391 million in military aid to Ukraine and dangled a White House meeting that Ukrainian President Volodymyr Zelensky desperately sought and still hasn't gotten.

The House Intelligence Committee, which spearheaded the impeachment inquiry, heard from 17 witnesses who testified to Trump's efforts to bully Ukraine into acceding to his personal demands. But House managers are pressing the Senate to call additional witnesses, like Bolton, who can provide firsthand knowledge of Trump's pressure campaign.

Fifty-one senators need to vote in favor of calling witnesses for the motion to pass. There are currently 45 Democrats, two independents who caucus with Democrats, and 53 Republicans in the Senate.

That means four Republican senators need to side with the Democratic caucus for the Senate to call witnesses.

In the Republican caucus, only Sens. Mitt Romney of Utah and Susan Collins of Maine have publicly indicated they would vote in favor of calling witnesses to testify.

Sen. Lamar Alexander of Tennessee, once considered a possible pro-witness Republican, announced Thursday night that he would not vote in favor of witnesses.

Sen. Lisa Murkowski of Alaska, another closely-watched potential swing vote on the matter, confirmed Friday afternoon that she will also vote against calling more witnesses.

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