(CNN) South Carolina Sen. Lindsey Graham is aiming to quash a subpoena for his testimony before an Atlanta-area special grand jury investigating former President Donald Trump's efforts to overturn the 2020 election results in Georgia.
"I just filed a motion to quash the subpoena. We'll see what the court says," the Republican senator told CNN on Wednesday, after his lawyers filed in federal court in South Carolina to block the subpoena.
Fulton County District Attorney Fani Willis, who is leading the investigation into Trump and his allies, said in court filings that the grand jury needed to hear from Graham about at least two calls Graham made to Georgia Secretary of State Brad Raffensperger and his staff in the wake of the 2020 election.
"During the telephone calls, the Witness questioned Secretary Raffensperger and his staff about reexamining certain absentee ballots cast in Georgia in order to explore the possibility of a more favorable outcome for former President Donald Trump," Willis wrote in her court filing seeking Graham's testimony. "The Witness also made reference to allegations of widespread voter fraud in the November 2020 election in Georgia, consistent with public statements made by known affiliates of the Trump Campaign."
Fulton County Superior Court Judge Robert McBurney, who is overseeing the grand jury, signed off on the subpoena, saying, "The Court finds that the Witness, based on the substance and timing of the telephone calls he personally made to Georgia Secretary of State Brad Raffensperger, is a necessary and material witness in this investigation."
In Graham's filing to block the subpoena, his attorneys said the senator's calls to Georgia officials were legislative activity and that his activities are protected under the Constitution's speech and debate clause.
"Senator Graham did not inject himself into Georgia's electoral process, and never tried to alter the outcome of any election. The conversation was about absentee ballots and Georgia's procedures," according to Graham's court filing. His contact with Georgia officials "is legislative activity falling under Senator Graham's fact-finding and oversight responsibility as the then-Chairman of the Senate Judiciary Committee and a sitting United States Senator required to determine whether to certify electoral votes before a joint session of Congress."
Raffensperger told CNN in November 2020 that Graham -- a South Carolina Republican who was then-chairman of the Senate Judiciary Committee -- hinted that Raffensperger should try to discard some Georgia ballots during a statewide audit.
"He asked if the ballots could be matched back to the voters," Raffensperger told CNN's Wolf Blitzer on "The Situation Room" at the time. "And then he, I got the sense it implied that then you could throw those out for any, if you look at the counties with the highest frequent error of signatures. So that's the impression that I got."'
"It was just an implication of, 'Look hard and see how many ballots you could throw out,'" Raffensperger added.
Asked if he was trying to pressure the secretary of state to toss legal ballots, Graham told CNN at the time, "That's ridiculous." Graham said he was trying to figure out how signatures were verified on mail-in ballots for a variety of battleground states.
On Wednesday, reporters pressed Graham on whether he would appear before the grand jury if a judge orders it.
"Call me when the court rules," Graham said.