Senate Republicans expressed optimism that they will defeat an upcoming vote for additional witnesses and end U.S. President Donald Trump’s Senate impeachment trial later this week.

“I’m optimistic,” Sen. John Cornyn (R-TX), the former Republican whip, said, referring to defeating the motion to bring in new witnesses, the Wall Street Journal reported Thursday.

Senate Majority Leader Chuck Schumer (D-NY) conceded on Wednesday that winning the four Republicans they need to allow additional witnesses to testify is “unlikely,” the New York Times revealed.

“We’ve always known it will be an uphill fight on witnesses and documents, because the president and [Senate Majority Leader] Mitch McConnell [R-KY] put huge pressure on these folks,” Schumer declared during a break in the impeachment trial on Wednesday.

Senate Majority Whip John Thune (R-SD) said, according to CNN:

I think the facts are all out there. I don’t think that anything that [Trump’s former national security adviser John Bolton is] going to say changes the facts … I think people kind of know what the fact pattern is.

Democrats have mainly been calling for new testimony from Bolton and Trump’s chief of staff Mick Mulvaney.

The New York Times, citing an unpublished manuscript from an upcoming book from Bolton, recently claimed that the former White House official made new revelations that go to the heart of Democrats’ impeachment and removal case against the president.

Trump has denied Bolton’s reported allegations.

Thune, the Senate’s No. 2, expressed confidence that the Senate trial will not go past Friday, the Hill added.

Sen. Martha McSally (R-AZ) proclaimed via Twitter on Wednesday, “I have heard enough. It is time to vote,” suggesting she does not want to hear from additional witnesses.

I have heard enough. It is time to vote. — Martha McSally (@SenMcSallyAZ) January 30, 2020

After two weeks in the Senate, 13 witnesses, and 28,000 pages of evidence, it is time for the Senate to vote and return its focus to the priorities of the American people… — Martha McSally (@SenMcSallyAZ) January 30, 2020

like lowering the cost of prescription drugs, improving our infrastructure, and solving real problems like the epidemic of veteran suicide. — Martha McSally (@SenMcSallyAZ) January 30, 2020

Many analysts have conceded that the GOP-controlled Senate will acquit Trump of the two articles of impeachment the House Democrats charged him with along party lines — abuse of power and obstruction of Congress.

In other words, as Thursday’s afternoon version of Politico’s Playbook aptly noted, impeachment “is all over but the shouting.”

“I’ve counted the votes long enough to be fully confident when it’s over,” Sen. Roy Blunt (R-MO), who served as House whip more than a decade ago, told the New York Times, according to the Playbook.

Early this week, the Hill acknowledged that GOP Senators are confident that there will be no additional witnesses, and the impeachment trial will end this week, noting:

Republican senators emerged from a caucus meeting Tuesday voicing confidence they will win a vote later this week that would block new witnesses from being called and end President Trump’s impeachment trial this week. While Republican sources acknowledged several senators are wrestling with the question of whether to bring in former national security adviser John Bolton as a witness, they said Democrats do not have the four GOP votes they need to win such a vote.

Echoing other Republican senators, Ted Cruz from Texas told reporters Tuesday that the vote on allowing more witnesses “could easily be close.”

Sen. Kevin Cramer (R-ND) projected Republicans would have at least 50 votes to defeat the motion on additional testimony.

“We’ve been 100 percent united in this process to this point, and it would be my hope that we can remain that way,” he said, according to the Hill.

“It’s either going to be 53, 52 or 51, some number that starts with five would be my guess would be the vote to not have witnesses,” Cramer added.

Chairman of the Senate Judiciary Committee Lindsey Graham (R-SC) also voiced optimism that Republicans will overcome the vote for additional witnesses.

Earlier this week, Graham predicted that if additional witnesses are allowed, a Republican majority will seek testimony from Joe Biden and his son Hunter over their activities in Ukraine as well as the “whistleblower” who triggered the impeachment with a complaint.

Republicans will also likely seek to hear from a Democratic National Committee official about whether there was 2016 U.S. presidential election interference on behalf of Democrats stemming from Ukraine.

“I feel good. I feel good that we’re in a good spot in terms of ending the trial sooner rather than later,” Graham said on Tuesday, the Hill reported.

During Tuesday’s Republican caucus meeting, Senate Majority Leader Mitch McConnell reportedly used the time to persuade his colleagues to remain united and vote no on additional witnesses.

Only two Republican senators — Mitt Romney (Utah) and Susan Collins (Maine) — have indicated they will vote in favor of additional witnesses and documents. McConnell reportedly focused on preventing more defections.