Updated on May 10 at 2:57 p.m. ET

Top Senate Republicans are standing behind President Trump’s decision to fire FBI Director James Comey, rejecting calls from Democrats and some in their own party for the Justice Department to appoint a special prosecutor to lead the investigation into Russian meddling in the 2016 election.

Majority Leader Mitch McConnell lent the president crucial support on Wednesday morning, calling out Democrats for hypocrisy and saying a new independent inquiry would “impede” the bipartisan investigation of the Senate Intelligence Committee. “Partisan calls should not delay the considerable work of Chairman Burr and Vice Chairman Warner,” the Kentucky Republican said in a floor speech, referring to the leaders of the official Senate probe. “Too much is at stake.” He chided Democrats for criticizing the president after they earlier called for Comey’s ouster over his handling of the Hillary Clinton email investigation, which many in the party believe helped to elect Trump as president. Senator John Cornyn of Texas, the second-ranking Republican, echoed McConnell, and Trump won similar support from Senator Charles Grassley, chairman of the Judiciary Committee.

McConnell made his comments moments after Minority Leader Charles Schumer renewed his call for a special prosecutor and demanded that Attorney General Jeff Sessions and the new deputy attorney, Rod Rosenstein, hold a private—and, if necessary, classified—briefing for the full Senate on the president’s decision. The White House has cited Rosenstein’s letter outlining Comey’s missteps as justification for the firing, and because Sessions has recused himself from the Russia investigation, it would be his decision to take the inquiry out of the FBI. Rosenstein, who was confirmed last month in a 94-6 vote, told the Senate during his confirmation hearing that he would appoint an independent counsel if he deemed it necessary. “If there was ever a time when circumstances warranted a special prosecutor, it is now,” Schumer said. Hours later, the New York Democrat returned to the Senate floor to revise his demand: It should not be Rosenstein or another political appointee, he said, but the highest-ranking career civil servant at the Justice Department that named a special prosecutor.

In a bid to underline the gravity of Trump’s move, Schumer gathered all Senate Democrats and asked them to be in their seats when the chamber gaveled into session on Wednesday morning. Ordinarily, very few senators listen to floor speeches and debate. And after McConnell sided with the president, Democrats began the process of grinding the Senate to a halt in protest of the Comey firing and the refusal to appoint a special prosecutor. In the Judiciary Committee, Democrats said they would invoke a rule limiting the panel’s hearing to two hours, and on the Senate floor, Senator Richard Durbin of Illinois cited the “constitutional question” involving the Comey firing when he objected to a routine procedural motion.

As Democrats took to the airwaves to blast Trump, the president was apparently watching—and tweeting from the White House on Wednesday morning. “Comey lost the confidence of almost everyone in Washington, Republican and Democrat alike,” he wrote. “When things calm down, they will be thanking me!” The president in particular went after Schumer and Senator Richard Blumenthal of Connecticut, needling the Democrat about his past prevarication about serving in Vietnam.

While the president called a few senators to inform them of his decision in advance, his firing of the FBI director—the first such mid-term ouster in 24 years—caught most of his party by surprise. The House is on recess, and in the first 16 hours after Tuesday’s announcement, not one of the House GOP’s top four leaders had responded to Comey’s removal. Speaker Paul Ryan is scheduled to appear on Fox News on Wednesday evening.

And although some Republicans questioned Trump, the criticism has thus far fallen short of the groundswell that would alter the political dynamic and force the Justice Department to appoint a special prosecutor. “I am troubled by the timing and reasoning of Director Comey’s termination,” Senator Richard Burr of North Carolina, the chairman of the Intelligence Committee, tweeted on Wednesday. He added that the move would “confuse” the committee’s Russia investigation. Comey was due to testify before the panel on Thursday, but Burr announced later on Wednesday that the FBI’s acting director, Andrew McCabe, would appear instead. The committee’s top Democrat, Senator Mark Warner of Virginia, said he wanted Comey to return as a private citizen next week.

For the most part, those Republicans that voiced concern about Comey’s firing did so in measured terms, couched in a desire to learn more about the president’s rationale. Senator John McCain of Arizona, an occasional critic of the president, said he was “disappointed” in the decision and reiterated his support for a select congressional committee to take over the Russia probe. But McCain’s frequent ally, Senator Lindsey Graham of South Carolina, backed Trump’s move, as did moderate Senator Susan Collins of Maine. GOP Senators Jeff Flake of Arizona, James Lankford of Oklahoma, Lisa Murkowski of Alaska, and Rob Portman of Ohio all questioned the firing or its timing. “Given the timing and circumstances of the decision, I believe the White House should provide a fuller explanation regarding the president’s rationale,” Portman said in a statement Wednesday.

In the House, statements from Republicans were scarce. But Representatives Justin Amash of Michigan and Barbara Comstock of Virginia, a top Democratic target in 2018, criticized the president and called for an independent investigation.

As Schumer pointed out, the Justice Department can decide on its own—without congressional action—to appoint a special prosecutor. Democrats have limited tools to force the issue. They can delay action in the Senate, including the confirmation of a new FBI director, but they do not have votes to obstruct the GOP agenda much more than they’ve already tried to do. It will take defections from top Republicans to pressure Trump, and with McConnell’s critical support on Wednesday, the GOP is sticking by the president for now.