Trump's new chief of staff needs to 'protect' Russia investigation, Democrat says Trump's new chief of staff should protect Bob Mueller, John Podesta says.

 -- President Trump's new White House chief of staff has "got to protect" the Russia investigation from "continued assault" by the president, said former Hillary Clinton campaign chair John Podesta, who also served as chief of staff to President Bill Clinton at the end of his second term.

Podesta told "This Week" co-anchor Martha Raddatz on Sunday that Trump's new chief of staff, Ret. Gen. John Kelly, is responsible for safeguarding the Justice Department and special counsel Robert Mueller, who heads the Russia probe, from interference by the White House.

"Maybe the most difficult thing he needs to do is ... protect the Justice Department, and he's got to protect Bob Mueller and the investigation that's going on there from the continued assault by the president and by the White House," Podesta said on "This Week."

"It's going to be his job to provide a bulwark against interference by the White House, which in the end of the day, [would] get them in more trouble rather than less,” Podesta said.

The president has repeatedly publicly slammed Attorney General Jeff Sessions over his recusing himself from the federal investigation of Russia's interference in the 2016 election and possible ties to Trump associates. The attorney general’s recusing himself ultimately led to the appointment of Mueller as special counsel.

At a press conference Tuesday, the president said he is "disappointed" in Sessions and that he wants the attorney general "to be much tougher on the leaks from intelligence agencies, which are leaking like rarely have they ever leaked before, at a very important level."

"We will see what happens. Time will tell. Time will tell," Trump added.

The president's public criticism has led some observers to question whether Trump might try to replace Sessions with an attorney general who could oversee the Russia probe and potentially remove Mueller.

That possibility has prompted warnings from some Republicans as well as Democrats.

“Any effort to go after Mueller could be the beginning of the end of the Trump presidency,” GOP Sen. Lindsey Graham of South Carolina said Thursday.

Beyond the Russia probe, Podesta said one question about Kelly's appointment as the new White House chief of staff is whether Trump will give the former general the authority fully do his job.

“I have no doubt that the president has told him that he has full authority,” Podesta said of Kelly. “The real question is will he allow him to exercise it.”