Even in uncertain times, there are routines that create a sense of normalcy: the start of a new school year, holiday decorations going up too early, Republicans in Congress suffering from selective bouts of blindness regarding the words and actions of President Trump.

After a congressional committee on Monday released a note and sexually suggestive drawing from Jeffrey Epstein’s lewd birthday book with what appeared to be the president’s signature, Republicans on Capitol Hill reverted to their most familiar crouch.

They claimed they had not seen something that was circulating widely online and dominating cable news, while those who conceded that it had crossed their radars echoed Mr. Trump’s assertion that the whole thing was “fake.”

“I haven’t seen it,” Representative Jim Jordan of Ohio, the chairman of the Judiciary Committee, told CNN of the drawing and signature. “Don’t buy it.”

Speaker Mike Johnson, who did not emerge from his office on Monday in the hours after the drawing was released, also eventually said he had not seen Mr. Trump’s note and the accompanying sketch of a woman’s figure.

“I’ve heard about it,” Mr. Johnson conceded to a PBS reporter who tailed him through the Capitol on Tuesday after his weekly news conference. “But no. And the White House say it’s not true. So.”