Senator Lindsey Graham listens during a press conference on refusing Russian annexation of portions of Ukraine, at the US Capitol, in Washington, D.C., on Thursday, September 29, 2022.
CNN  — 

South Carolina Sen. Lindsey Graham has asked the 11th Circuit US Court of Appeals to reverse a lower court ruling requiring him to testify before a Fulton County special grand jury investigating efforts by former President Donald Trump and his allies to overturn the 2020 election in Georgia.

In his appeal, the Republican senator requested an oral argument to make the case that he should not be forced to appear as a witness in the Georgia investigation, even with the questions limited in scope, according to a court filing from Graham’s lawyers.

“This appeal presents important questions of constitutional immunity concerning whether (and, if so, to what extent) a local district attorney can compel a sitting United States Senator to testify before a state special-purpose grand jury,” Graham’s attorneys wrote in Tuesday’s court filing.

Atlanta-based federal Judge Leigh Martin May, who denied Graham’s motion to quash his subpoena this summer, wrote in her decision that there were “considerable areas of inquiry” that were not legislative in nature that he should have to testify about.

Graham’s attorneys disputed that notion, writing that “these are backdoor ways to question Senator Graham about the motives for his legislative activity; unsupported by evidence; and outside the scope of the subpoena and special grand jury anyway.”

Graham has argued that his role as a US senator offers him considerable protection from being forced to testify. His attorneys cited the Constitution’s “Speech Or Debate Clause,” as well as “Sovereign Immunity,” and the “High-Ranking-Official Doctrine.”

“All three roads independently lead to quashal,” Graham’s attorneys wrote.

Prosecutors in Georgia have been interested in questioning Graham about calls he made to Georgia election officials regarding the state’s review of ballots cast in the 2020 presidential election. In one such call to Georgia Secretary of State Brad Raffensperger, Raffensperger came away with the impression that the senator was asking him to discard ballots, CNN has previously reported.

Graham has maintained that he never suggested ballots should be tossed, and his lawyers argued Tuesday that any calls to Georgia officials were part of Graham’s work as a sitting senator.

“At all times relevant to this matter, Senator Graham was the Chairman of the Senate Judiciary Committee, where—like his predecessors of both political parties—he held a hearing on elections and their administration, in fact, just two weeks after the 2020 presidential election. After the election, Senator Graham also had to decide whether to certify the results,” Graham’s attorneys wrote. “This made it incumbent on Senator Graham to investigate the widespread claims of election fraud and insecurity in advance of the vote.”

Prosecutors in the Fulton County district attorney’s office have argued that, after three failed attempts to quash his subpoena, Graham is repeating the same arguments, according to recent court filings. They are asking for the matter to be remanded back to a Fulton County Superior Court, which oversees the grand jury investigation.

Even if he were to lose this appeal, Graham has signaled he would take the case to the Supreme Court.

“I’ll go as far as I need to take it,” Graham told CNN last month. “I’m committed to standing up for the institution as I see it.”