Sen. Rand Paul (R-KY) is threatening to force the Senate to vote on subpoenaing Hunter Biden and the “whistleblower” in the event that his Republican colleagues side with Democrats and their demand for more impeachment witnesses — a move that would put some of them in vulnerable positions from a reelection standpoint.

While House Speaker Nancy Pelosi (D-CA) ultimately moved to transmit the articles of impeachment against President Trump to the Senate without her party’s demand for the promise of pre-trial witnesses, the debate is far from over. Sens. Susan Collins’ (R-ME) and Lisa Murkowski’s (R-AK) respective calls for the Senate trial to proceed in the mold of former President Bill Clinton’s trial solidified Majority Leader Mitch McConnell’s (R-KY) upper hand. However, both have signaled that they are open to calling forth witnesses after hearing opening statements.

Paul has a contingency plan. According to Politico, Paul “will make the Senate vote on subpoenaing the president’s preferred witnesses, including Hunter Biden and the “whistleblower” who revealed the Ukraine scandal in the event that four or more of his GOP colleagues side with Democrats and call for additional witnesses, putting at-risk GOP incumbents in more vulnerable positions.

“If you vote against Hunter Biden, you’re voting to lose your election, basically. Seriously. That’s what it is,” Paul said, according to Politico.

“If you don’t want to vote and you think you’re going to have to vote against Hunter Biden, you should just vote against witnesses, period,” he explained.

Paul says he would prefer to have the Senate trial dismissed as soon as possible, without calling witnesses. Nevertheless, if his colleagues concede to the demands of Democrats, Paul is prepared to demand more.

“My first preference would be to be done with it as soon as possible and not to have any witnesses,” Paul told the outlet.

“If they insist on having people like Bolton coming forward, my insistence will be not just one witness. But that the president should be able to call any witnesses that he deems necessary to his defense,” he added.

Paul’s plan follows reports of Collins working with a “fairly small group” of GOP senators to build support for impeachment witnesses.

“I am hopeful that we can reach an agreement on how to proceed with the trial that will allow the opportunity for both the House and the president’s counsel if they choose to do so,” Collins said at the time, according to Bangor Daily News.

Collins and Murkowski, however, indicated that they are not far from Paul in their views.

“Both Collins and Murkowski said on Wednesday they aren’t advocating for specific witnesses but simply want to retain the right to hear more evidence during the trial,” Politico reported.

“If he’s saying that both sides should have an opportunity, I agree with that, to call witnesses,” Collins stated. “We’ll make the call on which ones.”

“But it isn’t fair to just let one side call witnesses,” she said, agreeing with Paul but noting that his threat is “not [her] focus.”

“My focus is to be fair. And to have a dignified trial,” she told the outlet.

“Rand is 100% right. If we hear from witnesses we should hear from them all. Hunter, Joe, bullshit whistleblower, Schiff etc,” Donald Trump Jr. wrote on Thursday.

“If Republicans continue the Dem 1-way sham because they’re to [sic] weak to fight like Pelosi they don’t deserve to be re-elected,” he added:

Rand is 100% right. If we hear from witnesses we should hear from them all. Hunter, Joe, bullshit whistleblower, Schiff etc. If Republicans continue the Dem 1-way sham because they’re to weak to fight like Pelosi they don’t deserved to be re-elected. https://t.co/afaiFykmr3 — Donald Trump Jr. (@DonaldJTrumpJr) January 16, 2020

The House impeachment managers, which include House Intelligence Committee chairman Rep. Adam Schiff (D-CA) and House Judiciary Committee chairman Rep. Jerry Nadler (D-NY), will formally present the articles of impeachment to the Senate Thursday afternoon.