Mr. Patel has long been a part of efforts to fight off the Justice Department investigations into Mr. Trump and his allies. Earlier this year, as officials were pushing Mr. Trump to return records he had taken to Mar-a-Lago when he left office, Mr. Trump made him one of his representatives to the National Archives and Records Administration to deal with his records.
Legal experts say prosecutors try to avoid giving witnesses immunity, especially in high-profile cases, because it makes it much more difficult to prosecute the individual who received it. But prosecutors often ask a judge to grant it when they are confronted with a witness who has information that they believe is essential to completing the investigation.
Despite the government’s signaling that Mr. Patel was only a witness — not a subject of the investigation — he still refused to cooperate, and a federal judge declined to go along with an effort by prosecutors to compel his testimony. By removing the possibility that he could be charged with a crime based on evidence revealed through his testimony, the grant of immunity essentially made moot Mr. Patel’s Fifth Amendment claims.
Mr. Patel has increased his influence with Mr. Trump since the end of the presidency, maintaining his criticisms of the investigation into whether the Trump campaign conspired with Russia in the 2016 campaign.
Earlier this year, Mr. Patel told associates that he was expected to take on an even more central role in Mr. Trump’s legal defenses, currently coordinated by another Trump adviser, Boris Epshteyn, according to a person familiar with his comments.
In an appearance on Monday on “The Benny Show,” a pro-Trump podcast, Mr. Patel was asked whether he would accept a position as F.B.I. director if Mr. Trump were elected president in 2024.
“I’m all in with the boss, and you know that,” Mr. Patel said. “First, I tell people, let’s win the midterms. And then let’s see what he does and, you know, you and I think I know what he’s going to do. And then it’s a two-year lift and you know what, they’re going to come after us.”
