“The severity of this misconduct demands that elected officials in both parties set aside political considerations and do their constitutional duty,’’ the Massachusetts Democrat said on Twitter on Friday afternoon. “That means the House should initiate impeachment proceedings against the President of the United States.”

Warren became the first of the Democratic presidential candidates to unambiguously call for impeachment proceedings. Most senior Democrats in Congress have stopped far short of it following the delivery of Mueller’s 448-page report.

Senator Elizabeth Warren on Friday and Saturday called for lawmakers to start impeachment proceedings against President Trump, saying he obstructed Special Counsel Robert Mueller’s investigation into Russian meddling in the 2016 election.


The severity of this misconduct demands that elected officials in both parties set aside political considerations and do their constitutional duty. That means the House should initiate impeachment proceedings against the President of the United States. — Elizabeth Warren (@ewarren) April 19, 2019

Warren talked about Trump on the Rachel Maddow show Friday night.

Here is Elizabeth Warren's case for impeachment, and as you'd expect from her, it's solid. pic.twitter.com/DU5NlmZYn9 — Ethan Grey (@_EthanGrey) April 20, 2019

She spoke about it again Saturday morning at Keene State College in Keene, N.H.

LIVE: Yesterday I called on the House to begin impeachment proceedings. This is a matter of principle for me. https://t.co/X91tKMcn51 — Elizabeth Warren (@ewarren) April 20, 2019

Also Friday, the chairman of the House Judiciary Committee issued a subpoena for an unredacted version of Mueller’s report as Congress escalates its investigation. Trump and other Republicans dismissed the report’s findings.

The redacted version of Mueller’s report details multiple efforts Trump made to curtail a Russia probe he feared would cripple his administration. While Mueller declined to recommend that Trump be prosecuted for obstruction of justice, he did not exonerate the president, all but leaving the question to Congress.

The report stated, “If we had confidence after a thorough investigation of the facts that the President did not commit obstruction of justice, we would so state.”

House Speaker Nancy Pelosi has said she doesn’t support impeachment without bipartisan backing because it would be too divisive for the nation She signaled she wanted the House to continue to fulfill its constitutional oversight role.

‘‘We believe that the first article — Article 1, the legislative branch — has the responsibility of oversight of our democracy, and we will exercise that,’’ she said in Belfast on Friday.


Representative Jerrold Nadler, a New York Democrat who chairs the Judiciary Committee, said, ‘‘It now falls to Congress to determine the full scope of that alleged misconduct and to decide what steps we must take going forward.’’ He expects the Justice Department to comply by May 1.

On Twitter Friday, Warren said the report “lays out facts showing that a hostile foreign government attacked our 2016 election to help Donald Trump and Donald Trump welcomed that help. Once elected, Donald Trump obstructed the investigation into that attack.”

She said Mueller “put the next step in the hands of Congress,” adding in another tweet that “[t]o ignore a President’s repeated efforts to obstruct an investigation into his own disloyal behavior would inflict great and lasting damage on this country, and it would suggest that both the current and future Presidents would be free to abuse their power in similar ways.”

According to a Warren aide, the senator started to read the Mueller report Thursday during a plane ride back to Boston following campaign stops in Colorado and Utah.

Warren, according to the aide, felt it was her duty to say what she thought after reading the report but does not plan to emphasize impeachment on the campaign trail.

Mary Anne Marsh, a Boston-based Democratic strategist who is not connected to any presidential campaign, said Warren has been the first Democratic candidate to stake out numerous policy stances during the campaign. Her impeachment statement will force everyone else running for president to take a position, Marsh said.


“More often than not the field is reacting to her positions,” she said.

Warren’s call for impeachment proceedings, Marsh said, “shows she’s willing to lead.”

“She’s willing to make the hard calls,” Marsh said.

After the Mueller report’s release, Trump pronounced it ‘‘a good day’’ and tweeted ‘‘Game Over.’’ Top Republicans in Congress saw vindication in the report as well. On Friday, Trump was even more blunt, referring to some statements about him in the report as “total bullshit.”

House minority leader Kevin McCarthy said it was time to move on and said Democrats were attempting to ‘‘vilify a political opponent.’’ The California lawmaker said the report failed to deliver the ‘‘imaginary evidence’’ incriminating Trump that Democrats had sought.

Mitt Romney, a Republican who formerly served as Massachusetts governor and is now a senator from Utah, was among the few Republicans who spoke out forcefully about the findings.

Romney said Friday that he was “appalled” by the details.

“I am sickened at the extent and pervasiveness of dishonesty and misdirection by individuals in the highest office of the land, including the President,” he said in a statement posted to Twitter.

During the run-up to last fall’s midterm elections, some elements of the Democratic Party, led by billionaire activist Tom Steyer, sought to make impeachment of Trump a litmus test for congressional candidates.

However, many Democratic candidates skirted or downplayed that question, choosing instead to focus on other issues.


Now, liberals are pressing the House to begin impeachment hearings, and the issue is cropping up on the presidential campaign trail.

South Bend, Ind., Mayor Pete Buttigieg, a Democrat who is running for president, was asked Friday if Trump should be impeached as he made an appearance at a Stop & Shop union picket line in Malden .

“I think that Congress needs to make that decision,” he said. “I think he may well deserve it, but my focus, since I’m not part of Congress, but I am part of 2020, is to give him a decisive defeat at the ballot box, if he is the Republican nominee in 2020.”

On Friday, Julián Castro, a former housing secretary running for the Democratic nomination, said he thought “it would be perfectly reasonable’’ for Congress to open impeachment proceedings.

Senator Kamala Harris, a California Democrat who is running for president, told MSNBC on Thursday that she also thinks Mueller should testify. When asked about impeachment proceedings, she told that outlet, “I think that there’s definitely a conversation to be had on that subject, but first I want to hear from Bob Mueller.”

Cory Booker, the New Jersey senator running for president, was asked about impeachment during a campaign trip to Nevada. Specifically in regard to impeachment, he said, ‘‘There’s a lot more investigation that should go on before Congress comes to any conclusions like that.’’

In the House, Representative Alexandria Ocasio-Cortez of New York is now signed on to an impeachment resolution from fellow Democratic Representative Rashida Tlaib of Michigan.


But senior leaders remain cool to the idea.

Representative Steny Hoyer of Maryland, the number two in the House Democratic leadership, told CNN on Thursday, “Based on what we have seen to date, going forward on impeachment is not worthwhile at this point.” However, Hoyer quickly revised his comments, saying “all options are on the table.”

Liz Goodwin and Martin Finucane of the Globe staff contributed to this report. Material from the Associated Press was used. Danny McDonald can be reached at daniel.mcdonald@globe.com. Follow him on Twitter @Danny__McDonald.