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.