Sources: McCarthy worried about being subpoenaed by Jan. 6 commission

"There is a lot of drama right now and Kevin is in a perilous position," said a third Republican source. "Whether it's the January 6th commission, or if the Justice Department comes calling, he has information about the rally, the insurrection and Trump's words and state of mind."

Democrats and even some Republicans have suggested that McCarthy should be a witness during any congressional investigation into the January 6 attack -- particularly given the phone call he had with Trump on that day.

But it's unclear how real a threat that is. Thanks to the deal Katko negotiated, the current bill gives McCarthy the power to appoint two of the five Republican members of the commission and, with Senate Minority Leader Mitch McConnell, the commission's vice-chair. A majority of Republican appointees could block any effort to subpoena McCarthy.