ATLANTA — A week after Donald J. Trump declared his second candidacy for president, there was a fresh reminder on Tuesday of his ongoing legal entanglements when one of his closest allies on Capitol Hill, Senator Lindsey Graham of South Carolina, was forced to testify before a Georgia special grand jury that is investigating election interference by Mr. Trump and his advisers.
Mr. Graham’s lawyers had fought for months to keep him from having to testify, taking their effort all the way to the Supreme Court. But his legal team, which includes Donald McGahn, Mr. Trump’s former White House counsel, ultimately failed, leaving Mr. Graham to potentially face questions about whether he coordinated with the Trump campaign or others as they sought to overturn Georgia’s 2020 election results in Mr. Trump’s favor.
Like a number of other recent witnesses called before the special grand jury, Mr. Graham avoided walking into the Fulton County courthouse through the front door on Tuesday morning to give testimony in the closed-door proceeding. His lawyers have previously said that Mr. Graham is not a target of the Georgia investigation.
“Today, Senator Graham appeared before the Fulton County special grand jury for just over two hours and answered all questions,” his office said in a statement on Tuesday afternoon. “The senator feels he was treated with respect, professionalism and courtesy. Out of respect for the grand jury process, he will not comment on the substance of the questions.”
His appearance was a victory for Fani T. Willis, the district attorney in Fulton County, who is leading the investigation and has indicated that it could result in a multidefendant racketeering or conspiracy case. Underscoring Mr. Trump’s legal challenges, Mr. Graham’s appearance took place a few blocks away from the U.S. Court of Appeals for the 11th Circuit, which heard arguments in the afternoon in a case that could determine whether a special master should review documents seized in August from Mr. Trump’s Florida home.
Mr. Graham’s testimony comes as three other high-profile allies of Mr. Trump continue to fight orders to travel to Atlanta to testify. All three — Mark Meadows, the former White House chief of staff; Michael Flynn, Mr. Trump’s former national security adviser; and Newt Gingrich, the former House speaker — have appealed rulings that said they had to comply with the subpoenas.
Mr. Trump announced on Nov. 15 that he would seek another term. Even before he officially kicked off his new campaign, he publicly attacked Ms. Willis and other prosecutors investigating him at a rally early this year as “vicious, horrible people” who are “mentally sick.”
Such rhetoric has done little to prevent the nearly two-year-old Georgia investigation from grinding forward. The special grand jury is expected to finish its work reviewing voluminous documents and testimony in the coming months. While it cannot issue indictments, it is expected to issue a report that could serve as the basis for indictments by a regular grand jury.
Mr. Gingrich had argued thathis willingness to sit for an interview with the House committee investigating the Jan. 6 attack on the Capitol should preclude him from testifying in the Atlanta criminal investigation. But in a court filing last week, Mr. Gingrich’s lawyer, John A. Burlingame, revealed that the Jan. 6 committee had rescinded its invitation. Mr. Gingrich continued to argue, however, that he should not have to testify in Atlanta.
Mr. Graham once repudiated Mr. Trump as a “race-baiting, xenophobic bigot” but became one of his staunchest allies in the Senate, repeating Mr. Trump’s false claims about stolen elections.
Mr. Graham’s legal team won a partial victory, convincing federal courts that he should be shielded from some types of questions under the Speech or Debate Clause of the U.S. Constitution, which generally protects members of Congress from discussing their legislative work in court.
But the courts ruled that such immunity did not apply regarding matters that were “political in nature rather than legislative,” leaving Mr. Graham subject to questions about what led him to make calls soon after the November 2020 election to Brad Raffensperger, Georgia’s secretary of state. Mr. Raffensperger has said that Mr. Graham suggested rejecting all mail-in votes from counties with high rates of questionable signatures. Mr. Graham, who at the time was chairman of the Senate Judiciary Committee, has said that he was acting in his official capacity.
In August, U.S. District Judge Leigh Martin May ruled that Mr. Graham should not be shielded from questions having to do with his “alleged coordination” with the Trump campaign or other third parties regarding postelection efforts in Georgia. She also ruled that he would have to answer questions about any efforts to “cajole” or “exhort” Georgia election officials to change their election processes or results, and questions about “public statements or speeches he made outside of Congress about the 2020 elections.”
After his testimony, Mr. Graham was scheduled to appear on Tuesday night at a gun club in Powder Springs, Ga., in a rally supporting Herschel Walker, the former N.F.L. football star and Trump-backed Republican candidate for U.S. Senate.
On Jan. 4, 2021, Mr. Walker falsely claimed on Twitter that “Country wide election fraud” had occurred.
Sean Keenan contributed reporting.