Comey's testimony expected to shut down Capitol Hill

Rep. Jackie Speier: "This will be watched as much as the Watergate hearings."

Rep. Peter King (R-N.Y.) will watch the hearing Thursday, but he is worried about Trump retaliating on Twitter in real time.

"He can only hurt [his case]," King said in an interview. "He should just stay quiet."

King, who said Comey's statement released by the Senate Intelligence Committee today was "very positive" for the president -- because it appeared to back up his claim that Comey repeatedly told him he wasn't under investigation -- said Trump should leave any rebuttal to his lawyer.

"The danger is he responds to something inflammatory that some Democratic senator is going to ask, a leading question with a criminal implication ... and the president’s going to tweet quickly without checking all his records," he added.

They have also cancelled votes planned for Friday, giving members an opportunity to leave Washington -- and questions from the Capitol Hill press corps about Comey's testimony -- a day early.