WASHINGTON — As the Senate begins preparations for an impeachment trial next month, many Republican members are questioning the wisdom of having President Donald Trump call witnesses and are instead discussing a speedy resolution.

Republican senators have been holding talks about the likely trial and few see the benefit of a slate of witnesses testifying on behalf of the president, fearful that the benefits of a defense filled with contentious testimony that may not necessarily exonerate him could be overshadowed by political rancor and gamesmanship.

Senate Majority Leader Mitch McConnell, who has mostly avoided looking like he is putting his thumb on the scale on how to conduct the trial, will be keeping tabs on his members to know when to a call for a vote. He said that after the presentations from each side, senators could decide "that they've heard enough and believe they know what would happen and could move to vote on the two articles of impeachment."

Trump has indicated that he wants former Vice President Joe Biden, his son Hunter, the whistleblower and House Intelligence Committee Chair Adam Schiff, D-Calif., to testify.

Others want to get to a Senate vote much more quickly.

"What I want to do is try the case based on the record produced in the House," Sen. Lindsey Graham, R-S.C., said. "I don't want to prolong this trial any longer than necessary. I think impeachment is hurting the country, and I have no desire to make it a long trial."

The White House suggested publicly on Thursday that Trump s open to whatever kind of process the Senate decides on.

"The President has done nothing wrong, and the House should stop this ridiculous illegitimate impeachment sham, but he is absolutely ready for anything in the Senate," said deputy press secretary Hogan Gidley.

Privately, a source familiar with the strategy cautions that Trump wants two things: to ensure the process in the Senate is fair, and that a trial gives the president the due process rights that the White House believes he was deprived of in the House.

Republican leaders say they believe there aren't enough votes to remove Trump from office — 67 are required — so it would be unnecessary to extend a trial and risk the potential for weeks of partisan political fighting.

"I think there's going to be a desire to wrap this up in somewhat of a timely way, you know, given the fact that most people know what the outcome is in advance," said Sen. John Thune of South Dakota, the Republican vote-counter.

At a weekly GOP closed-door lunch on Tuesday with Jonathan Turley, a constitutional law professor at George Washington University who appeared on behalf of Republicans on the House Judiciary Committee to argue against impeachment, senators discussed what the process would be and whether witnesses should be called.

Sen. Mike Braun, R-Ind., said the public has already heard the evidence. "We’ve heard everything up to this point three times," Braun said on NBC News Now.

The proceedings in the Senate would begin with the House presenting its case for impeachment and Trump's lawyers presenting their defense. That is the point where many Republicans are hoping the trial can end. But to conclude the trial, 51 senators would have to agree to do so.

And it's up to the president to decide whether to call witnesses. Trump has said that he's eager for the trial to start, believing he’ll get a fair trial and be given the ability to call people who will defend him or distract from the issue at hand.

Trump "just says he wants to fully vindicate himself, so what that ends up being we don't know," Braun said.

Rep. Mark Meadows, R-N.C., who speaks with Trump regularly, said he believes the president will want to call witnesses "to have his name cleared."

"There is a general belief among some members of Congress that additional witnesses, including the whistleblower, will highlight the coordinated and partisan nature of this impeachment process," Meadows said in an interview.

Democrats are open to a trial with witnesses.

"That wouldn't be a real trial, would it?" Sen. Richard Durbin, D-Ill., said about a process that doesn't include witnesses. "In other words, what they're saying is, we don’t want to hear evidence."

Democrats haven't decided on their preferred witness list. But some have said they'd like to hear from people close to Trump who didn't cooperate with the House investigation, including Secretary of State Mike Pompeo, former Energy Secretary Rick Perry and perhaps even the president's personal lawyer, Rudy Giuliani.

"I'm not going to get into the specifics, but it should be fair, it should be bipartisan, and it should let the facts come out," said Senate Democratic Leader Chuck Schumer of New York.

CORRECTION (Dec. 12, 12:18 p.m.): A previous version of this article misstated the university where constitutional scholar Jonathan Turley is a professor. It is George Washington University, not George Mason University.