Impeaching Donald Trump may be the dream of some Democrats, but party leaders poised to take control of the House of Representatives won’t go there even after the president ousted Attorney General Jeff Sessions.

“This is a constitutionally perilous moment for our country and for the president,” Representative Jerrold Nadler, who’s expected to become chairman of the House Judiciary Committee in January, said after Trump forced Sessions to resign on Wednesday and named Matthew Whitaker, a critic of Special Counsel Robert Mueller’s Russia inquiry, as acting attorney general.

But Nadler and other House Democratic leaders are still stopping short of citing the constitutional power of impeachment that they could wield — and that some party activists are demanding they pursue. It’s a move that could backfire by coming off as partisan overkill and prove futile because impeachment by the House would be unlikely to result in removal of the president by the Senate, where the Republicans increased their majority in Tuesday’s elections.

“Now is not the time to consider impeachment,” Representative Steny Hoyer of Maryland, the No 2 House Democrat, said in a statement. “Special Counsel Mueller must be allowed to complete his investigation. The president’s decision to ask for Attorney General Sessions’s resignation underscores the need for Congress to take action to protect that investigation.”

Instead, the leaders are emphasizing that once they gain control of House committees they’ll use their power to call hearings and issue subpoenas to investigate possible Trump campaign collusion with Russia and whether the president is seeking to obstruct justice. They’re also reviving a push for legislation intended to shield Mueller from interference.

And at least for now, they’re treating a constitutional showdown on removing Trump from office as a step too far.

“The Justice Department is a crime scene, and we’re busy roping it off with yellow tape,” said Representative Jamie Raskin of Maryland, a Democratic member of the Judiciary Committee, who calls impeachment a distraction at this point.

Read more: All You (and Trump) Should Know About Impeachment

Asked about impeachment at a news conference on Wednesday, Trump ridiculed the idea. “Do you impeach somebody because you’ve created the greatest economic success in the history of our country?” he said, adding “these people are sick and, you know what? They have to get their bearing.”

Even before Sessions resigned at Trump’s demand, almost a third of Democratic House members in the current Congress supported articles of impeachment proposed by Texas Representative Al Green, and they and some newly elected members campaigned on that approach.

Steyer’s Campaign

Outside activists plan to redouble pressure for House action. Billionaire Tom Steyer, whose Need to Impeach Group has run television ads, portrayed Sessions’s dismissal and Whitaker’s appointment as a turning point.

“Together with millions of Americans, I demand that members of Congress” act “to protect the investigation and start impeachment proceedings against Trump immediately,” Steyer said in a statement Thursday.

Allan Lichtman, a history professor at American University who wrote a book titled “The Case for Impeachment’,’ said Democrats at least need to be prepared.

‘“The onus may well fall on the House if in fact the special counsel’s investigation is crippled,’’ he said. “This is the time to show some steel in the Democratic backbone.”

Combine any constraints that may be put on Mueller “with all the other evidence of obstruction of justice, and you have a vastly stronger case on obstruction of justice than Republicans had with Bill Clinton in 1998,” he said.

Mueller’s investigation has already secured indictments and guilty pleas from a Trump campaign chairman, a former national security adviser and other associates. Trump’s former personal lawyer, Michael Cohen, has been cooperating with Mueller and the U.S. attorney’s office in Manhattan after pleading guilty to tax evasion and other crimes this year.

But any impeachment move would have to be “the result of a process — not the beginning of one,’’ Democratic Representative Gerald Connolly of Virginia, who is in line to be chairman of the House Oversight subcommittee on Government Operations, said before Sessions was removed. Moving prematurely would be “politically toxic” for Democrats, he said.

The party’s takeover of the House Intelligence and Judiciary Committees all but guarantees a flurry of subpoenas intended to force Trump associates to answer questions and provide documents. Under Republicans, those panels largely blocked such moves by Democrats while pursuing the contention that the investigation into Russian influence in the 2016 election was tainted from the beginning by anti-Trump bias in the FBI and Justice Department.

Trump warned at a news conference Wednesday of a “war-like posture” if the Democratic House opens new probes. He pledged the Republican-held Senate would retaliate by digging into “questionable things” done by Democrats, including “leaks of classified information.”

House Democratic Leader Nancy Pelosi of California, who is poised to become speaker in January, responded at her own news conference that “we have a constitutional responsibility to have oversight” and that Democrats would resort to subpoenas if necessary.

House Republicans have said any impeachment actions by Democrats would only backfire politically.

Representative Doug Collins of Georgia, who’s in the running to become the top Republican on the Judiciary Committee, said that Nadler was making “baseless impeachment plans.”

“We’re here to remind Mr. Nadler that a House majority doesn’t give liberals license to chase political vendettas at deep cost — and no benefit — to the hardworking Americans who trust us to honor the law first by following it ourselves,” he said.

Then there’s the ultimate question of what action by the House would really mean: Removing an impeached president would require a two-thirds vote in the GOP-controlled Senate.

Facing that reality, impeachment “would be an enormous waste of resources at a time when efforts need to be focused on protecting Mueller and his investigation,” said Raskin, the House Judiciary member.