3 things to know as Trump's impeachment trial heads to acquittal vote Wednesday

A final Senate vote on whether President Donald Trump will be acquitted in his impeachment trial is now set for Wednesday after Democrats on Friday lost a weeks-long push to allow witnesses in order to make their case.

The Republican-controlled Senate voted against witnesses 51-49 after Democrats failed to persuade four GOP moderates to join them.

That, despite a new bombshell about former national security adviser John Bolton that seemed to have potential to upend the trial.

Here are three takeaways from Friday’s dramatic session.

1) A push for Bolton to testify fails

On Friday, just before the Senate reconvened, new revelations regarding Trump’s alleged actions regarding Ukraine surfaced when The New York Times reported on more details from Bolton’s unpublished manuscript.

According the Times’ reporting, President Trump directed Bolton in May to help Rudy Giuliani, the president’s personal attorney, to secure a meeting with Ukrainian President Volodymyr Zelenskiy -- two months before Trump's July 25 call with Zelenskiy and the earliest known instance of Trump being directly involved in the Ukraine pressure campaign.

ABC News has not independently reviewed the manuscript, but The New York Times reported that Bolton claims that the president asked him to call the Ukrainian president to "ensure Mr. Zelenskiy would meet with Mr. Giuliani, who was planning a trip to Ukraine to discuss the investigations that the president sought.”

Trump denied the account in a statement to The Times, saying that he “never instructed John Bolton to set up a meeting for Rudy Giuliani, one of the greatest corruption fighters in America and by far the greatest mayor in the history of N.Y.C., to meet with President Zelensky.”

"That meeting never happened,” Trump said.

Adam Schiff, the lead House impeachment manager, addressed the new claims in The New York Times’ report speaking on the Senate floor Friday. Schiff challenged the Senate to hear from Bolton: “So, here you have the president saying John Bolton is not telling the truth. Let's find out.”

“Let's put John Bolton under oath. Let's find out who's telling the truth. Trial is supposed to be a quest for the truth let’s not fear what we will learn as Mr. Cipollone said let's make sure that all the facts come out.”

“This drip drip drip from the Bolton book is going to keep coming. Seems to me a vote against considering witnesses is basically an admission that nothing can change your mind about this President's conduct,” Democratic Sen. Mark Warner of Virginia tweeted Friday evening,

2) Senate votes against hearing any witnesses

The Senate voted to not allow witnesses in the trial, despite Democrats’ hard push earlier in the week to sway key Republicans who had indicated they would might be interested in hearing from Bolton.

GOP Sens. Susan Collins of Maine and Mitt Romney of Utah were the only Republicans who voted with Democrats in favor of including witnesses.

Two Republicans targeted by Democrats -- Sens. Lamar Alexander from Tennessee and Lisa Murkowski of Alaska -- voted no, after announcing they would ahead of Friday's proceedings.

Murkowski, in a statement. said that she has “come to the conclusion that there will be no fair trial in the Senate.”

“I don’t believe the continuation of this process will change anything,” she said. “It is sad for me to admit that, as an institution, the Congress has failed.”

Murkowski also voiced concern that the process would become further politicized “and drag the Supreme Court into the fray,” as well as Chief Justice John Roberts.

“We are sadly at a low point of division in this country,” Murkowski said.

Before the vote -- despite the long odds --- House impeachment managers kept up their push for witnesses.

“The evidence in the record is sufficient, it is sufficient to convince the president on both articles of impeachment more than sufficient, but that's simply not how trials work,” lead House manager Adam Schiff said. “As any prosecutor or defense lawyer would tell you, when a case goes to trial both sides call witnesses and subpoena documents to bring before the jury.”

Schiff argued that trial process “happens every day,” in “courtrooms all across America. There is no reason why this impeachment trial should be any different.”

3) What happens next

One of the senate's GOP leaders, Sen. Roy Blunt, of Missouri, said the final vote on acquittal is scheduled for 4 p.m. on Wednesday.

That's a day after President Trump is set to head to the Capitol to give his State of the Union address Tuesday evening and an awkward moment for Trump that the White House and congressional Republicans wanted to avoid. They had hoped the impeachment cloud would have been removed by then.

President Bill Clinton gave a State of the Union address during his 1999 Senate impeachment trial before eventually being acquitted.

ABC News’ Stephanie Ebbs, Allison Pecorin, Trish Turner, Mary Bruce, Olivia Rubin, and John Parkinson contributed to this report.