Former Special Counsel Robert Mueller resigned during a press conference Wednesday morning, during which he made what some Democrats are calling “an impeachment referral” against President Donald Trump.
Mueller reiterated that the Justice Department could not confidently say that President Trump did not commit a crime.
“If we had had confidence that the President clearly did not commit a crime, we would have said so,” he said.
However, Mueller told reporters that the Department could not bring charges against Trump because a sitting president “cannot be charged with a federal crime while he is in office.”
The former Special Counsel suggested that it’s both reasonable to believe the president committed a crime and that impeachment proceedings could be an appropriate course of action, but that power does not sit in the hands of the Justice Department.
Instead, he said, the “Constitution requires a process other than the criminal justice system to formally accuse a sitting president of wrongdoing.”
Some Democrats saw his remarks as an impeachment referral to Congress, as progressive Democrats in the House and several 2020 presidential contenders supported taking action.
New Jersey Sen. Cory Booker and Vermont Sen. Bernie Sanders both expressed support for impeachment proceedings. Booker said Congress has a “legal and moral obligation” to do so.
South Bend, Ind., Mayor Pete Buttigieg called Mueller’s statement “as close to an impeachment referral as it gets.”
California Sen. Kamala Harris tweeted, “It’s our constitutional obligation.”
New York Sen. Kirsten Gillibrand—who previously took the side of House Speaker Nancy Pelosi who opposes rushing to impeachment—changed her tune and said it’s time to begin the proceedings. Pelosi remained firm in her stance that Congress should not move toward impeachment without having “all the facts.”
Despite the House Speaker’s beliefs, more than 40 lawmakers now support the calls for an impeachment inquiry.
“We’re beyond talking about this in terms of political implications,” Massachusetts Rep. Jim McGovern and chairman of the Rules Committee told WGBH radio. “We have to do what’s right.”
Mississippi Rep. Bennie Thompson, chairman of the Homeland Security Committee, said the president “egregiously obstructed justice,” and would support an impeachment inquiry.
Other Democrats urged Congress to continue investigating the president’s criminal activity, independently.
In the event that Congress moves forward with impeachment proceedings, Mueller said he would prefer not to testify.
“The report is my testimony,” said Mueller. “I would not provide information beyond that which is already public in any appearance before Congress.”
More must-read stories from Fortune:
—Robert Mueller resigns, says charging Trump with crime was ‘not an option’
—Pelosi says Trump is becoming ‘self-impeachable’
—What would impeachment look like in Trump’s America?
—Rep. Rashida Tlaib is unapologetic about her expletive-filled call for Trump’s impeachment
—Trump tweets that Democrats want to impeach him for being ‘too successful’