Mueller shifts 2020 ground on impeachment: Analysis Democrats have accelerated conversations about what to do next.

Special Counsel Robert Mueller said Wednesday that his work has formally concluded and that he’d even prefer not to speak of the matters raised by his investigation again.

But what may be Mueller’s first and last public words on the weighty subject of his investigation only quickened conversations among Democrats about what to do next. Those conversations center on a word that Democratic Party leaders are only uttering recently and somewhat reluctantly.

Still, it is clear that the impeachment of President Donald Trump is now under active consideration by more and more Democrats who lead Congress and who are running for president.

For the Democrats seeking the party’s nomination in 2020, the position for the House to go forward with impeachment proceedings is now practically mainstream. Within moments of Mueller’s extraordinary public statement on Wednesday, Sen. Cory Booker and Sen. Kamala Harris called for Congress to start impeachment proceedings.

“Robert Mueller’s statement makes it clear: Congress has a legal and moral obligation to begin impeachment proceedings immediately,” Booker, who sits on the Senate Judiciary Committee, tweeted Wednesday after Mueller’s public address. “Beginning impeachment proceedings is the only path forward.”

Booker and O’Rouke joined a growing roster of Democratic candidates – including Sen. Elizabeth Warren, Mayor Pete Buttigieg, and former Reps. Beto O’Rourke and Julian Castro – and a long list of progressive groups who are on record saying impeachment is now the appropriate path.

Even holdouts on the question – including Sen. Bernie Sanders and former Vice President Joe Biden, the two leaders in public polling – acknowledge the fact that that may be where things are headed.

Mueller’s very decision to speak publicly on his last day at the Department of Justice raised questions about the truthfulness of Attorney General William Barr. It also posed thorny legal and constitutional questions for another branch of the federal government to consider.

“If we had had confidence that the president clearly did not commit a crime, we would have said so. We did not, however, make a determination as to whether the president did commit a crime,” Mueller said in front of cameras on Wednesday.

He cited longstanding Justice Department policy holding that charging a president with a federal crime would be “unconstitutional,” in his words. And Mueller went on to reference the Constitution in another way that seemed to reference impeachment without saying the word.

“The opinion says that the Constitution requires a process other than the criminal justice system to formally accuse a sitting president of wrongdoing,” he said.

That other “process,” as Mueller or any lawyer knows, is known as impeachment, and is under the purview of Congress. For months, 2020 campaigns and Democratic political strategists have worried the politics of an impeachment fight on Capitol Hill could backfire in Republicans’ favor in the lead up the next presidential election.

In an interview in March, House Speaker Nancy Pelosi said impeachment was “not worth it,” and many in her party agreed that it would be a distraction to focus on. Pelosi hasn’t shifted that stance, even as she thanked Mueller Wednesday for providing “a record for future action both in the Congress and in the courts.”

House Judiciary Chairman Jerry Nadler, D-N.Y., accused Barr of “lying” repeatedly about the special counsel’s findings. “With respect to the impeachment question at this point, all options are on the table and nothing should be ruled out,” Nadler said.

In recent weeks, as the Trump administration has refused to comply with subpoenas and barred some members of the administration from testifying before House committees, tunes have begun to change among top Democrats.

A senior staffer on one campaign, whose candidate has not yet called for impeachment proceedings to begin, wrote to ABC over the weekend, “All of the presidentials are looking for that tipping point when the investigative process hits a dead end and there’s no choice but impeachment. I don’t think we’re quite there yet but getting closer.”

During an interview last week, congressman and presidential candidate Tim Ryan said if Mueller and other White House personnel cited in his report would not testify on Capitol Hill, Congress would likely need to “take the next step.”

“I just think we've got to bring the American people along right now,” Ryan, D-Ohio, told ABC News. “There needs to be a real education process as to what really happened. The president did obstruct justice. It's on multiple occasions. It's pretty clear. But if people back in the Midwest don't know that, then we will look like we're overreaching, and it'll turn into a political football.”

Building on that analogy, Mueller handed off the work to Congress. His work may be done, but this high-stakes game goes on.