Senate Judiciary Committee Chairman Lindsey Graham Lindsey Olin GrahamMomentum growing among Republicans for Supreme Court vote before Election Day Video of Lindsey Graham arguing against nominating a Supreme Court justice in an election year goes viral Warning signs flash for Lindsey Graham in South Carolina MORE (R-S.C.) says he will vote against a motion to subpoena Hunter Biden if a majority of colleagues agree next week that additional witnesses and documents need to be summoned for President Trump Donald John TrumpUS reimposes UN sanctions on Iran amid increasing tensions Jeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Trump supporters chant 'Fill that seat' at North Carolina rally MORE’s impeachment trial.

If Republican colleagues introduce a motion to subpoena former Vice President Joe Biden Joe BidenMomentum growing among Republicans for Supreme Court vote before Election Day Trump expects to nominate woman to replace Ginsburg next week Video of Lindsey Graham arguing against nominating a Supreme Court justice in an election year goes viral MORE’s son, Graham said “I vote against it.”

ADVERTISEMENT

Republicans have threatened to weaponize the debate over impeachment witnesses by warning that if Democrats and GOP moderates vote to subpoena Bolton, Mulvaney and other senior Trump advisers, they’ll respond in kind by calling controversial witnesses such as the Bidens.

Sen. Ran Paul (R-Ky.) has argued that Trump’s defense team should be allowed to call whatever witnesses they want.

“The president gets to call anybody he thinks would be good for his defense, the prosecution can call who they want, but I don’t think we should selectively call witnesses that don't like the president,” Paul said last week.

Sen. John Kennedy John Neely KennedyMORE (R-La.) says he hasn’t made a decision yet on calling additional witnesses, but he predicts that Trump’s lawyers would want to cross-examine the Bidens.

“I feel pretty confident, though I don’t know it for a fact, that the defense team is going to want to call its witnesses, including but not limited to the Bidens, [and] as a fact witness the whistleblower,” he said.

ADVERTISEMENT

Senate Majority Leader Mitch McConnell Addison (Mitch) Mitchell McConnellMomentum growing among Republicans for Supreme Court vote before Election Day Trump expects to nominate woman to replace Ginsburg next week Video of Lindsey Graham arguing against nominating a Supreme Court justice in an election year goes viral MORE (R-Ky.) has also opened the door to subpoenaing Hunter Biden.

“When you get to that issue, I can’t imagine that only the witnesses that our Democratic colleagues would want to call would be called,” he said.

Graham acknowledged he doesn’t yet know of three other Republicans to vote against subpoenaing Hunter Biden but his opposition to the move all but guarantees that it won’t happen.

“I need some Republicans who would say as much as I want to know more about Burisma and the Bidens, this is not the venue. I’ve got to find four,” he said.

Republicans control 53 seats and Democrats have 47. A motion to subpoena witnesses would deadlock on a 50-50 vote.

ADVERTISEMENT

If Graham says that hauling Hunter Biden before the Senate would be going down too much of a political rabbit hole, it’s extremely hard to imagine moderates such as Sens. Susan Collins Susan Margaret CollinsJeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Trump supporters chant 'Fill that seat' at North Carolina rally Momentum growing among Republicans for Supreme Court vote before Election Day MORE (R-Maine), Lisa Murkowski Lisa Ann MurkowskiMomentum growing among Republicans for Supreme Court vote before Election Day Collins: President elected Nov. 3 should fill Supreme Court vacancy Barrett seen as a front-runner for Trump Supreme Court pick MORE (R-Alaska) or Mitt Romney Willard (Mitt) Mitt RomneyMomentum growing among Republicans for Supreme Court vote before Election Day Toobin: McConnell engaging in 'greatest act of hypocrisy in American political history' with Ginsburg replacement vote The Memo: Court battle explodes across tense election landscape MORE (R-Utah) doing so.

Graham said there should be an investigation into Hunter Biden’s business dealings in Ukraine and what he did as a highly compensated board member of Burisma Holdings, a Ukrainian gas company, but he warned that the impeachment trial is not the appropriate venue.

“I don’t want to call Hunter Biden. I don’t want to call Joe Biden. I want someone to look at this when this is done,” he said Friday.

“I don’t think it’s wrong for us to look at the Biden connection in the Ukraine, the $3 million given to the vice president’s son by the most corrupt company in the Ukraine,” he added.

But Graham said he’s going to oppose subpoenas for them because “this needs to end,” referring to the impeachment trial.

“To my Republican friends, you may be upset about what happened in the Ukraine with the Bidens but this is not the venue to litigate that,” he said.

He believes it would be more appropriate for a special investigator such as former FBI Director Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE, who investigated Trump, or someone of his nonpartisan stature to do so.

—Jordain Carney contributed. Updated at 2:53 p.m.