Pressure is growing on Senate Minority Leader Charles Schumer Chuck SchumerPelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' 3 reasons why Biden is misreading the politics of court packing Cruz blocks amended resolution honoring Ginsburg over language about her dying wish MORE (D-N.Y.) to endorse the start of impeachment proceedings against President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE as the idea gains support from his leadership, including several of the Senate’s most influential women.

The third- and fourth-ranking Senate Democrats, Sens. Patty Murray Patricia (Patty) Lynn MurraySenate Democrats introduce legislation to probe politicization of pandemic response Trump health officials grilled over reports of politics in COVID-19 response CDC director pushes back on Caputo claim of 'resistance unit' at agency MORE (Wash.) and Debbie Stabenow Deborah (Debbie) Ann StabenowOVERNIGHT ENERGY: Trump rollbacks could add 1.8 billion tons of greenhouse gas emissions over 15 years: analysis | Intensifying natural disasters do little to move needle on climate efforts | Experts warn wildfire smoke could worsen COVID-19 GAO report finds brokers offered false info on coverage for pre-existing conditions Democrats back away from quick reversal of Trump tax cuts MORE (Mich.), are now both backing an inquiry into Trump’s possible impeachment.

ADVERTISEMENT

Murray, the assistant Senate Democratic leader, announced her position on Sunday and a day later said she has seen enough evidence to warrant impeachment proceedings.

“What we know from the Mueller report is deeply concerning and the president has been not responding to subpoenas and to requests for information,” said Murray, who usually flies under the news media’s radar.

“So to me this is very concerning, and I think it’s not just about this president, but it’s about what bar we have presidents in the future about obstruction of justice,” she told reporters at the Capitol Monday evening.

Stabenow, the Senate Democratic policy chair and a longtime Schumer ally, on Monday also said she would support House Democrats moving forward with a formal impeachment process, going farther than Schumer and Speaker Nancy Pelosi Nancy PelosiPelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' On The Money: Anxious Democrats push for vote on COVID-19 aid | Pelosi, Mnuchin ready to restart talks | Weekly jobless claims increase | Senate treads close to shutdown deadline Trump signs largely symbolic pre-existing conditions order amid lawsuit MORE (D-Calif.), who have held off on endorsing the “I-word."

“The Mueller report describes extremely serious instances of the President of the United States trying to obstruct justice. I support the ongoing investigations in the House of Representatives and would stand with my colleagues in the House if they decided to launch a formal impeachment inquiry. No one is above the law,” Stabenow said in a statement.

Schumer has stayed in lockstep with Pelosi, who has put the brakes on starting the impeachment process in the House, the first step of which would be to hold a formal impeachment inquiry.

In May, he endorsed Pelosi’s go-it-slow approach, even after Rep. Justin Amash Justin AmashInternal Democratic poll shows tight race in contest to replace Amash Centrist Democrats 'strongly considering' discharge petition on GOP PPP bill On The Trail: How Nancy Pelosi could improbably become president MORE (Mich.), a Republican who recently quit the GOP, accused the president of impeachable conduct.

“My view is that we ought to get all the facts out, the way the House is doing now with Leader Pelosi,” he said at a May 21 press conference.

“If you have a little patience all the information will come out and then decisions will be made,” he added.

But Democrats who support impeachment say that time is getting short, as they believe the process would have to begin before the start of the 2020 election year or risk appearing too politicized.

“Impeachment has to start before the voting starts, otherwise people will say that Trump’s fate should be determined by the voters,” said one Democratic senator who requested anonymity to discuss party strategy.

Murray’s announcement on Sunday was a significant development given her position in leadership. She gave Schumer a heads-up but didn’t have a strategic conversation with him about whether it was the right move to now call for an impeachment inquiry to begin.

Schumer on Monday declined to comment on Murray’s emergence as the highest-ranking Democrat to call for impeachment proceedings to begin.

The senator who spoke to The Hill about internal party politics said the question of how to handle impeachment proceedings could be a litmus test in a future Senate leadership election, depending on whether Trump wins reelection and Democrats regain majority control of the Senate.

If Trump loses to the Democratic nominee, then the question will be moot and Pelosi’s decision to hold off on impeachment will be hailed as the right move.

But if the president wins reelection and Senate Democrats remain stuck in the minority, that could spur restlessness in the Democratic caucuses and second-guessing about the decision not to impeach Trump, the senator predicted.

A second Democratic senator said it’s the “general view” that it will be too late to begin impeachment proceedings next year although this senator cautioned that view could change depending on what evidence against Trump emerges.

Murray announced her position on Sunday in a statement, joining all seven House Democrats from Washington state in calling for the start of the impeachment process. Washington’s other senator, Maria Cantwell Maria Elaine CantwellHillicon Valley: Subpoenas for Facebook, Google and Twitter on the cards | Wray rebuffs mail-in voting conspiracies | Reps. raise mass surveillance concerns Key Democrat opposes GOP Section 230 subpoena for Facebook, Twitter, Google Hillicon Valley: Zuckerberg acknowledges failure to take down Kenosha military group despite warnings | Election officials push back against concerns over mail-in voting, drop boxes MORE (D), did not do so, however.

“I agree with my fellow members of the Washington delegation that, as we have learned more about the gravity of the potential threats to our democracy identified in Special Counsel Mueller’s report, it has become clear the House should begin proceedings to determine whether the president’s actions necessitate impeachment,” Murray said in a rare Sunday statement.

People who know Murray well say she doesn’t expect other colleagues to necessarily follow suit but thinks it’s important to speak from the heart and make clear where she stands.

Murray and Stabenow are the fourth and fifth members of Schumer’s leadership team to call for the start of a formal impeachment inquiry.

Sen. Elizabeth Warren Elizabeth WarrenHillicon Valley: Subpoenas for Facebook, Google and Twitter on the cards | Wray rebuffs mail-in voting conspiracies | Reps. raise mass surveillance concerns On The Money: Anxious Democrats push for vote on COVID-19 aid | Pelosi, Mnuchin ready to restart talks | Weekly jobless claims increase | Senate treads close to shutdown deadline Democratic senators ask inspector general to investigate IRS use of location tracking service MORE (D-Mass.), the vice chair of the Senate Democratic Caucus, Senate Democratic Outreach Chairman Bernie Sanders Bernie SandersThe Hill's Campaign Report: Trump faces backlash after not committing to peaceful transition of power Bernie Sanders: 'This is an election between Donald Trump and democracy' The Hill's 12:30 Report: Trump stokes fears over November election outcome MORE (I-Vt.) and Chief Deputy Whip Jeff Merkley Jeffrey (Jeff) Alan MerkleyThe Hill's Morning Report - Sponsored by The Air Line Pilots Association - Trump, Biden renew push for Latino support Sunday shows - Trump team defends coronavirus response Oregon senator says Trump's blame on 'forest management' for wildfires is 'just a big and devastating lie' MORE (D-Ore.) had previously called for the start of impeachment proceedings in the House. Warren and Sanders are running for president.

Heidi Hess, the co-director of Credo Action, a liberal advocacy group, said Murray’s statement puts more pressure on Pelosi and Senate Democratic allies who back her cautious strategy to move ahead with impeachment proceedings.

"Momentum is growing rapidly in favor of impeachment with yet another Senate Democrat in leadership urging House Democrats to hold Donald Trump accountable for his lawlessness," Hess said Monday. "Speaker Pelosi should listen well to the calls of not only almost half of her caucus, but also those of her colleagues in the Senate as well.

“It's beyond time to officially move forward with impeachment — not just doing so in what 'essentially' counts as an inquiry. Continuing to wait or playing at semantics amounts to tacit approval of Trump's cruel, racist policies and his impeachable offenses," she added.

Brian Fallon, a former senior aide to Schumer, predicted that Schumer will not allow any delight between himself and Pelosi, even though more Democratic lawmakers are backing the start of impeachment proceedings.

“I think Schumer is going to stay in lockstep with Pelosi. But someone as high-ranking as Murray endorsing the push for impeachment clearly shows what side has the momentum at this point,” he said.

Not all members of Schumer’s leadership team have been willing to go as far as Murray and Stabenow in calling for the start of impeachment proceedings.

Senate Democratic Whip Dick Durbin Richard (Dick) Joseph DurbinThe Hill's Morning Report - Sponsored by Facebook - Trump previews SCOTUS nominee as 'totally brilliant' Feinstein 'surprised and taken aback' by suggestion she's not up for Supreme Court fight Grand jury charges no officers in Breonna Taylor death MORE (Ill.) on Monday said he didn’t know exactly how to interpret Murray’s statement from Sunday.

“I asked her what she meant by that and she said, ‘Continuing investigation of what [Trump] has said and done,’” Durbin said.

Asked if he endorses the start of an impeachment inquiry in the House, Durbin said, “I don’t know what that means.”

“If you ask me whether the investigation by [Chairman Jerrold] Nadler and the House Judiciary Committee should continue, yes,” Durbin said, noting that the House Judiciary Committee’s investigation could lead to articles of impeachment.

But another Democratic senator who spoke on condition of anonymity said it would be important to formally declare a House investigation an “impeachment inquiry” so that the courts would give it more deference when deciding whether to compel the White House to comply with subpoenas.