Washington — Whether the Senate hears from witnesses in President Trump's impeachment trial is a question that will be settled in the coming days, after the House impeachment managers and the president's legal team have finished their opening arguments. This is the approach advocated by Senate Majority Leader Mitch McConnell, who says he's modelling the process on Bill Clinton's impeachment trial in 1999. In that trial, House managers interviewed three witnesses, and video excerpts from the interviews played on the Senate floor, during the trial.
At the top of the list of witnesses Democrats would call if they have the opportunity are former national security adviser John Bolton and acting White House chief of staff Mick Mulvaney, both of whom they believe have more information about the pressure campaign Mr. Trump is accused of carrying out against the Ukrainian president. One of the articles of impeachment charges charges Mr. Trump with abuse of power for making the announcement of investigations of former Vice President Joe Biden and his son, Hunter Biden, a pre-condition for the release of congressionally approved Ukrainian military aid and a White House visit.
With 53 Republicans in the Senate, it will require four to vote with Democrats to require that the Senate hear from witnesses in Mr. Trump's impeachment trial. Here are the GOP senators to watch:
Susan Collins, of Maine
In response to the "mischaracterization and misunderstanding" of where she stands, Collins tweeted a statement that said in part, "While I need to hear the case argued and the questions answered, I tend to believe having additional information would be helpful. It is likely that I would support a motion to call witnesses at that point in the trial just as I did in 1999."
She said she wouldn't support attempts by either side to do subpoena documents or witnesses before opening statements and the senators' Q&A period. And she has made no decision on any particular witnesses yet.
In Bangor earlier this month, Collins said, "I am working with a group of Republican Senators and our leaders to see if we can come to an agreement on some language that would be in the initial resolution setting out the parameters of the trial in the Senate that would include an opportunity for the House to call witnesses and the president's council to also call witnesses."
Lisa Murkowski, of Alaska
Murkowski also indicated that she wanted to defer making a decision on witnesses until after she's heard both sides make their cases. She told reporters in Anchorage Saturday that she wants to ensure "that we have a process that will allow for that determination" — whether witnesses or documents are needed, according to the Associated Press. "But I want to have that at a point where I know whether or not I'm going to need it."
Mitt Romney, of Utah
On January 13, Romney said he would like to hear from witnesses but will hold off on voting on this until both sides have made opening arguments. He told reporters he'd vote against Senator Chuck Schumer's proposal to guarantee from the outset that witnesses are heard in the Senate trial.
Instead, he said, "There's the Clinton impeachment model, which is to say we have opening arguments, and then we have a vote on whether or not to have witnesses that's the approach I favor. At that point I'll be voting in favor of considering witnesses."
Lamar Alexander, of Tennessee
Earlier this month, Alexander said he'd like to be able to decide whether or not there would be additional witnesses or additional documents.
"I want to make sure I have a chance to vote on whether we need additional witnesses or additional documents," he said, "and I'll decide whether we do after I hear the case and asked my questions."
Pat Toomey, of Pennsylvania
In December, Toomey didn't rule out voting against witnesses, but he also said he wasn't ready to decide, he told NBC News' Chuck Todd on "Meet the Press."
"I'm not comfortable with making that decision right now," he said. "But it might come to that, Chuck. You know, there might be a lot of agreement on facts and the case that can be stipulated. I think there's a big disagreement about what rises to a level of impeachment. So, after the arguments are made, then I think that's the time to decide whether witnesses are necessary."
If the Senate agrees to hear from witnesses, there are two Republican senators who have said they might want to hear from witnesses that the president's lawyers might want to call, too.
Kevin Cramer, of North Dakota
Cramer told reporters earlier this month that the first few days of the trial would impact the decision on whether more witnesses or evidence would be needed.
"I want to be informed by the case that's brought the prosecutors, the House managers, and listen to the (president's) defense and then determine whether or not we need any further evidence or more witnesses," Cramer said.
At the time, he said he wouldn't hear "from any witnesses." However, he added, "If we get to the point of where we start hearing from witnesses, I don't expect that we're only going to hear from witnesses from one side." He added that he thought the Senate process would be "very fair" and both sides would have the chance to make their cases.
Ted Cruz, of Texas
Cruz has proposed a "reciprocity" resolution. If Democrats get witnesses in the Senate trial, so should Republicans, he argues. He made the case for witnesses for the GOP side on "Fox Futures" in mid-January."
If the prosecution gets a witness, the defense gets a witness. If the prosecution gets two, the defense gets two. That means, if the prosecution gets to call John Bolton, then the president gets to call Hunter Biden. And I got to tell you, the Democrats are terrified about seeing a witness like Hunter Biden testify, because they don't want to hear evidence of actual corruption, of corruption, potentially, of Joe Biden, corruption that occurred during the Obama administration. They blocked all those witnesses in the House. They're not going to succeed in blocking them in the Senate. If they want to go down the road of witnesses, that means the president enjoys the rights to due process, which means he can call witnesses and lay out his defense.