Sen. John Barrasso (R-Wy.) took a jab at Democratic presidential nominee Joe Biden on Tuesday, saying he’s “not sure what he recalls” about his time as Senate Judiciary Committee chairman. 

“I don’t know what Joe Biden remembers when you look back at the time when he played such a role in the hearings for Judge [Robert] Bork. He was the one who basically turned on what became a political circus,” Barrasso said at a Senate GOP press conference.

His comments come as Senate GOP leaders move to fill a Supreme Court vacancy left by Justice Ruth Bader Ginsburg, who died of complications from pancreatic cancer on Friday. Democrats, including Biden, have argued that the seat on the conservative-majority court should be left vacant until after the November election.

Biden, who chaired the Senate Judiciary Committee from 1987 to 1995, oversaw several Supreme Court nominations. Barrasso's comments appeared to be a nod to attacks from the Trump campaign questioning Biden's cognition. 

"I don't know if he remembers that he was the one that smeared Clarence Thomas," Barrasso added. "I don't know if Joe Biden remembers that he was one that led the filibuster of Justice [Samuel] Alito."

"I’m not sure what he recalls of any of those, but I do know that the Democrats today here will continue to remember those lessons and use them against whoever it is that President Trump nominates," Barrasso said.

Senate Republicans are getting increasingly close to securing the votes needed to approve a Supreme Court nominee, whom Trump said he’d announce by Saturday. Their move to consider a nominee less than two months before an election is a reversal from their stance in 2016, when they refused to move then-President Obama's final Supreme Court nominee, Merrick Garland.

Democrats have retaliated by invoking the so-called two-hour rule, which can be used to limit the ability to hold committee hearings after the Senate has been in session for more than two hours.