Katzmann grounded Monday’s ruling in the 1974 landmark decision in United States v. Nixon, which declared the president cannot be shielded from a criminal investigation. Katzmann emphasized the importance of a grand jury’s work and a state investigation, especially in this situation involving Trump’s personal business rather than his activities in office.

The US v. Nixon case tested whether the Oval Office tapes tied to the Watergate cover-up were protected by executive privilege. In a unanimous decision, the court concluded that the fundamental demands of due process and need for evidence in a criminal trial overrode Nixon’s assertion that he had a constitutional right to keep communications private.

In the case of Trump v. Vance, Katzmann wrote that it would “exact a heavy toll on our criminal justice system to prohibit a state from even investigating potential crimes committed by him for potential later prosecution, or by other persons, not protected by any immunity, simply because the proof of those alleged crimes involves the President.”