Dr. Anthony Fauci, who helped lead the country's COVID pandemic response, invoking the constitutional right against self-incrimination last week during a contentious Senate hearing on the response and the virus's origins has sparked a fierce legal – and political – debate whose origins date back to a late-1800s Supreme Court decision and that will likely be resolved in court. 

Sen. Rand Paul, the Senate committee chairman, argues the constitutional privilege no longer applies because the sweeping, preemptive pardon former President Joe Biden granted Fauci in 2025 extinguished any realistic threat of federal prosecution for the conduct under investigation. 

The Kentucky Republican senator also characterized Fauci’s repeated invocations as legally unsupported and announced that the committee will vote next week on whether to hold the former National Institute of Allergy and Infectious Diseases director, in contempt of Congress.

Fauci's attorneys strongly disagree. 

They maintain that, despite the pardon, Fauci still faces potential criminal exposure arising from future testimony – particularly if prosecutors were to allege that statements made under oath during the hearing constituted perjury or false statements. They also point to the possibility of state criminal investigations, which are beyond the reach of a presidential pardon.

The Legal Distinction: Presidential Pardons and the Fifth Amendment

At the center of the dispute is a well-established constitutional principle. The Fifth Amendment protects individuals from being compelled to provide testimony that could reasonably be used against them in a criminal prosecution. The privilege exists only when there is a genuine risk that truthful answers could expose the witness to criminal liability.

A full presidential pardon generally removes that risk for the federal offenses it covers. 

More than a century ago, in Brown v. Walker (1896), the Supreme Court held that once a witness has “received a pardon, he can no longer set up his privilege, since he stands, with respect to such offense, as if it had never been committed.” Put differently, if there is no remaining possibility of federal prosecution for the underlying conduct, there is ordinarily no constitutional basis to refuse to answer questions about it.

The Supreme Court added an important qualification in Burdick v. United States (1915), holding that a pardon is not effective unless it is accepted by its recipient. Acceptance of a pardon may carry an implication of guilt, and an individual may reject the pardon in order to preserve the Fifth Amendment privilege. Once accepted, however, the recipient generally loses the ability to invoke the privilege with respect to the pardoned federal offenses.

Even so, presidential pardons have important limits. They apply only to federal crimes, not violations of state law, and they cannot immunize conduct occurring after the pardon is issued. 

Likewise, a pardon does not protect someone who later commits perjury or makes false statements under oath. As a result, testimony given after the pardon may itself create new criminal exposure, and testimony that could implicate state offenses may still support a valid Fifth Amendment claim.

Biden’s Pardon and Fauci’s Hearing

On January 19, 2025 – his final full day in office – Biden granted Fauci a full and unconditional pardon covering any federal offenses he may have committed between January 1, 2014, and the date of the pardon. 

Biden said the pardon was intended to protect Fauci from what he described as politically motivated prosecutions arising from his public service during the pandemic. The pardon, however, does not extend to conduct occurring after its issuance.

During Wednesday’s hearing, Paul and other Republican senators on the Senate Committee on Homeland Security and Government Affairs, questioned Fauci extensively about gain-of-function research, pandemic-era public health policies, federal funding decisions, and records relating to the government’s response to COVID-19. 

On the advice of counsel, Fauci repeatedly declined to answer, invoking the Fifth Amendment more than 100 times. In his prepared opening statement, Fauci acknowledged that invoking the privilege “pains me,” noting his longstanding history of cooperating with congressional investigations, but explained that his attorneys had advised him that responding could expose him to legal risks.

Paul argued that Biden’s pardon eliminated any realistic possibility of federal prosecution for Fauci’s pre-2025 conduct, leaving him without a valid Fifth Amendment basis for refusing to testify. 

Fauci's legal team responded that the pardon does not insulate him from new criminal charges, including potential perjury or false-statement allegations based on testimony given during the hearing itself. They also noted that several state attorneys general have publicly discussed possible investigations related to the pandemic, meaning state criminal exposure cannot be categorically ruled out.

Legal scholars have observed that the dispute presents a difficult constitutional question. 

Although the pardon plainly removes federal criminal liability for covered past conduct, courts have recognized that the Fifth Amendment may still apply where truthful testimony could expose a witness to new criminal liability or to prosecution under state law. 

Because Congress has rarely confronted a witness protected by such a broad preemptive presidential pardon, there is relatively little judicial guidance addressing the precise interaction between those principles in the congressional oversight context. 

What Comes Next

Paul has scheduled a committee vote on a resolution recommending that Fauci be held in contempt of Congress. If the committee approves the measure, and it is ultimately adopted by the full Senate, the matter could be referred to the Department of Justice for possible enforcement, potentially setting the stage for litigation over the validity of Fauci’s Fifth Amendment claims.

Whether Fauci was legally entitled to invoke the Fifth Amendment may ultimately depend on how courts balance the broad immunity conferred by Biden’s pardon against any remaining risk of post-pardon criminal exposure, including perjury, false-statement, or state-law offenses. 

Until a court addresses those issues, the dispute is likely to remain one of the most closely watched constitutional questions arising from Congress’s ongoing investigations into the federal government’s handling of the COVID-19 pandemic.