President Biden’s “full and unconditional pardon” of his son Hunter could have an unexpected and, for the Bidens, unwelcome result — depriving Hunter of the Fifth Amendment’s shield and leaving the first son vulnerable to a subpoena to take the stand and testify under oath.

The possibility that the pardon could backfire on the first family could impart new life to efforts by congressional Republicans — now the majority — to investigate the Biden family for their business dealings. That subject led to the opening of an impeachment inquiry against the 46th president that stalled.  

One of the leaders of that effort, Congressman Jim Jordan, took to X in the wake of the pardon to declare, “Democrats said there was nothing to our impeachment inquiry. If that’s the case, why did Joe Biden just issue Hunter Biden a pardon for the very things we were inquiring about?” 

The lawmaker who led the impeachment inquiry, Representative James Comer, went on Newsmax to share that he looks forward to “talking to Attorney General Bondi about” the younger Biden’s inability, after the pardon, to invoke the Fifth Amendment. He was referring to the former Florida attorney general who is Trump’s nominee to replace Attorney General Garland, Pam Bondi. On Sunday, via social media, Mr. Comer resumed using the appellation “Biden Crime Family” to describe the Wilmington clan. 

President Biden is, under Department of Justice policy, shielded from prosecution while in office — that prohibition is what ended Special Counsel Jack Smith’s twin prosecutions of President Trump after he won last month’s election. Once Mr. Biden leaves office, though, he will be vulnerable to prosecution under the parameters laid out in Trump v. United States, where all official presidential acts are presumptively immune. Some — like the issuance of pardons — enjoy absolute immunity.    

The president’s act of clemency for his son is extraordinarily broad, covering all “offenses against the United States which he has committed or may have committed or taken part in during the period from January 1, 2014 through December 1, 2024.” The younger Mr. Biden has already been convicted of lying on a gun form, and was set to go to trial on tax evasion charges. 

The period prescribed by the pardon begins just before the younger Mr. Biden joined the board of Burisma, a Ukrainian holding company that has come under scrutiny by congressional Republicans, who accuse the Bidens — the president, his brother James, and Hunter — of trading on the family’s political influence for profit.    

While the Biden justice department focused on prosecuting Hunter for gun and tax crimes that stemmed from his drug and alcohol addiction, House Republicans were focused  on what Mr. Comer calls the Biden family’s “criminal enterprise.” The GOP has long alleged that the Bidens took bribes from foreign entities, and that the justice department slow-walked investigations. The family denied those allegations.

Following the president’s pardon of his son, in any event, the incoming Trump administration may be incentivized to further probe the Biden family. The pardon issued to Hunter by the president covers any federal offenses the president’s son could conceivably have committed over the last decade.

That pardon means that Mr. Biden fils no longer faces legal jeopardy for any of them. Alexander Hamilton wanted the pardon power to be “as little as possible fettered or embarrassed,” and President Biden’s pardon gives Hunter what the Journal calls “an immunity almost without precedent.”   

A lawyer who once served as the United States pardon attorney, Margaret Love, told Politico that she has “never seen language like this in a pardon document that purports to pardon offenses that have not apparently even been charged, with the exception of the Nixon pardon” extended to the 37th president by his successor, President Ford. That was a “full, free, and absolute pardon unto Richard Nixon for all offenses against the United States.”

Enter the Constitution’s Fifth Amendment, which ordains that no person “shall be compelled in any criminal case to be a witness against himself.” This means that a defendant in a criminal case can refuse to take the stand if he faces legal jeopardy and that his refusal to testify cannot be spun as an admission of guilt. Judges instruct juries to this effect.

Now that criminal liability has been lifted for Hunter Biden, the Fifth Amendment will be much less available for him in both court and before Congress, a setting courts have considered to be legal in nature and therefore within the jurisdiction of the amendment. That means that a Republican Congress or President Trump’s Department of Justice could subpoena his testimony — possibly about the actions of his father. 

The younger Mr. Biden would likely contest any effort to compel him to talk under oath. He could invoke the specter of state charges, which the Supreme Court has ruled cannot be wiped away by presidential pardon. He could also argue that testifying could expose him to forms of future legal jeopardy not covered by his father’s pardon. 

The failure to testify before Congress when legally obligated to do so is also a crime, though prosecuting it requires a criminal referral to the Department of Justice. With Republicans in control of the House of Representatives and the Department of Justice, that scenario could enter the realm of possibility. 

Two allies of Trump  — Peter Navarro and Stephen Bannon — were sent to prison for contempt for failing to testify before the House January 6 Committee. Bannon, fresh out of prison, has been vociferously calling for retaliation.