Appeals court puts pause on Lindsey Graham's grand jury testimony in Ga. election investigation

A federal appeals court on Sunday temporarily halted a lower court's ruling mandating that Sen. Lindsey Graham, R-S.C., testify before a grand jury in Georgia that is investigating pro-Trump efforts to sway the state's 2020 presidential election results.

In a brief order, the 11th U.S. Circuit Court of Appeals sent the ruling back down to the district court, instructing the judge there to weigh any potential changes to Fulton County's grand jury subpoena to Graham in alignment with the Constitution's speech and debate clause.

The clause, which offers lawmakers certain legal protections when they are acting in their official capacities, is at the heart of Graham's challenge to the subpoena for his testimony.

Graham had been scheduled to testify Tuesday.

The appellate circuit ruled that the district court should "determine whether [Graham] is entitled to a partial quashal [rejection] or modification of the subpoena to appear before the special purpose grand jury based on any protections afforded by the Speech or Debate Clause of the United States Constitution."

"Following resolution of the partial-quashal issue on limited remand, the matter will be returned to this Court for further consideration," the appellate judges wrote.

The ruling is the latest development in Fulton County's investigation of efforts to overturn the 2020 race -- a probe that turned into a pitched legal battle with Graham after Georgia prosecutors sought his testimony earlier this year.

District Court Judge Leigh Martin May had ruled on Friday that "further delay of … Graham's testimony would greatly compound the overall delay in carrying out the grand jury's investigation" and "thus poses a significant risk of overall hindrance to the grand jury's investigation."

"The Court therefore finds that granting a stay would almost certainly result in material injury to the grand jury and its investigation," May wrote.

Fulton County District Attorney Fani Willis, a Democrat leading the investigation, first sought Graham's testimony in July.

The South Carolina legislator, a staunch ally of former President Donald Trump, became embroiled in the case over two calls he made to Georgia Secretary of State Brad Raffensperger shortly after the last presidential race.

Graham has since insisted that he was inquiring over how signatures on Georgia mail-in ballots were verified and was not pushing for any votes to be tossed in support of Trump. Graham's legal team says his calls should be protected under the speech and debate clause, arguing they were related to legislative work under his role as chair of the Senate Judiciary Committee at the time.

The Georgia grand jury probe was launched after Raffensperger, a Republican and the state's top elections overseer, was lobbied by Trump to "find 11,780 votes" -- the number the then-president needed to win the state over Joe Biden, who won Georgia (which was later re-confirmed by a full manual recount).

In seeking a grand jury earlier this year, Willis wrote to the court that she had reason to believe there was "a reasonable probability that the State of Georgia's administration of elections in 2020 … was subject to possible criminal disruptions." She previously told the Associated Press that she was examining Graham and Trump's calls with Raffensperger.

The Fulton County grand jury can make recommendations but does not have the power to indict, which would be up to another grand jury to weigh after the investigation.

Trump has insisted his pressure campaign in Georgia was appropriate and he did nothing wrong, claiming Willis is politically persecuting him.

ABC News' Alexander Mallin and Will Steakin contributed to this report.