At other points, he vented about Mr. Trump’s “painfully rambling” and “laborious” news conferences, or described arguments in which Mr. Trump accused Fauci of undermining him. Mr. Trump then argued officials shouldn’t wear masks at the event, saying it “sends the wrong signal,” but Fauci pushed back. In that same period, Fauci wrote about his worries that the Centers for Disease Control and Prevention would lose credibility if it didn’t loosen up on some restrictions. “I finished by looking him in the eye and telling him that if anybody is lying here it is he,” Fauci wrote. Fauci wrote an Oct. 12, 2021, entry that the senator “continues his assault on me.”