Even before President Donald Trump’s Friday morning tweetstorm, Senate Judiciary Chairman Charles E. Grassley was saying the next FBI director needs to be independent from the president.

The Iowa Republican said he does not think the nominee for the next FBI director will have any conflict of interest requiring recusal from the investigation into Russian interference in the 2016 election.

And he did not expect the nominee to have ties to the Trump presidential campaign or the presidential transition. That would seem to rule out Trump backers like former New York Mayor Rudy Giuliani and New Jersey Gov. Chris Christie.

“I think the president and the people close to the president don’t want to emphasize that any more. They’re going to get somebody entirely away from that as far as I can tell,” Grassley said.

That might be an open question given Trump’s Friday morning threat against the recently fired James B. Comey, in which the president said, “James Comey better hope that there are no ‘tapes’ of our conversations before he starts leaking to the press!”

Grassley said as part of an interview with Roll Call and The Associated Press for C-SPAN’s “Newsmakers” recorded Thursday that he wanted to see a list of potential candidates from the White House before he provided any advice on specific nominees.

“I would be happy to weigh in, but I’m not in the business of suggesting,” Grassley said. “Just somebody that’s independent and somebody who’ll do the job, and somebody that will have the respect of the people that are the FBI agents. That’s very important.”

Grassley suggested that perhaps someone could be pulled from the federal bench for the role, citing the example of William H. Webster, who served as FBI director in the 1970s and 1980s after being a federal appeals court judge based in Missouri.

Webster became a federal judge under Republican President Richard Nixon before being nominated to lead the FBI by Democratic President Jimmy Carter.

But Grassley conceded that it will be more difficult for even the least partisan choice to win bipartisan support in the current environment.

He did not specifically weigh in on any of the names floated so far, including Merrick Garland, the chief judge on the D.C. Circuit Court of Appeals who Grassley worked to block from being considered for the Supreme Court in the final year of the Obama administration.

“I think that Garland is an outstanding individual,” Grassley said Thursday, noting he had not reviewed Garland’s qualifications for the FBI position. “There’s not anything just about Garland himself that I can say no to.”

Grassley also said that it was important for the next FBI director to be responsive to his oversight requests, reiterating his issues with the organization under Comey. He said that at times private citizens could get information from the FBI through the Freedom of Information Act more quickly than he could as the chairman of the Judiciary Committee.

“We can pass laws and appropriate money, but also have the constitutional responsibility to make sure that these bureaucrats and agency heads and even the president of the United States does what the law requires in how the money’s spent,” he said.