In his final hours in the Oval Office, former President Joseph R. Biden Jr. issued Dr. Anthony S. Fauci, then the country’s top infectious disease expert, a pre-emptive pardon to shield him from what he expected would be retribution from President Trump and his allies.
But the pardon only covers what transpired before it was issued on Jan. 20, 2025. And as Senate Republicans grilled Dr. Fauci on Wednesday about his management of the Covid-19 pandemic response, the risk that Republicans accusing him of making a misrepresentation to Congress could drag the retired 85-year-old immunologist into fresh legal battles appeared too great for him to take.
Again and again, Dr. Fauci answered questions from the Senate Homeland Security and Governmental Affairs Committee by invoking his Fifth Amendment rights against self-incrimination.
The repeated refrain visibly angered Republicans, who accused him of being a “megalomaniac” and, more critically, “a liar,” given that lying to Congress is a federal felony.
“You’ve lied to the American people, and you’ve lied to this body, and you disgraced your profession by doing it,” said Senator Josh Hawley, Republican of Missouri.
The threat that Republicans would try to catch Mr. Fauci in a lie belied the argument, voiced by some on the panel, that the breadth of Mr. Fauci’s pardon ought to preclude him from being able to invoke the Fifth Amendment to discuss his official actions before the pardon was issued.
“You don’t have any rights under the Fifth Amendment, because you’ve been pardoned, as you very well know,” Mr. Hawley claimed, citing an 1896 Supreme Court decision, Brown vs. Walker.
Republicans, armed with the newly released text of a private diary Dr. Fauci kept through the ascent of the Covid-19 pandemic, asked him to explain several points in which his notes appeared to conflict, or at least challenge, his public statements about the origins of the coronavirus — and his advocacy for measures to contain it that were unpopular with the Republican base.
Those included whether the virus originated in a lab in Wuhan, China, whether that lab received funding that could have contributed to the virus’s development, and whether government public health officials believed the social distancing measures Dr. Fauci promoted would prevent its spread.
