The Court held that Article II and the Supremacy Clause of the US Constitution do not categorically preclude or require a heightened standard for the issuance of a state criminal subpoena to a sitting president.

"[4] After his election victory and taking office in 2017, Trump refused to give over his tax records and stated that voters were not interested in them.

Separately, as part of the city's ongoing criminal investigation into the Stormy Daniels scandal, Manhattan District Attorney Cyrus Vance Jr. in August 2019 subpoenaed Mazars for Trump's tax returns.

"[13] Prosecutors countered that Trump had "sweeping immunity" from a criminal probe while he was in office and that Trump was "seeking to invent and enforce a new presidential 'tax return privilege,' on the theory that disclosing information in a tax return will necessarily reveal information that will somehow impede the functioning of a President, sufficiently to meet the test of irreparable harm.

Observers recognized that the Justices treated Vance, which involved a subpoena related to a grand jury criminal investigation, and Mazars, involving subpoenas related to a Congressional investigation, very differently and expected there to be different results between the cases, with Vance likely to favor the release of the tax records.

Justices also spoke of possibly sending both cases to the lower courts with a set of standards to evaluate the subpoena requests.

Roberts wrote that former Chief Justice John Marshall established the principle 200 years earlier that no citizen, including the president, may escape the common duty to produce evidence when he is called upon during a criminal proceeding.

Kavanaugh wrote that he would have held the case to the standard established in United States v. Nixon,[27] which determined that a prosecutor must have a "demonstrated, specific need" for subpoenaing a President.

"[28] Alito wrote on his concern that the majority opinion would open the president to potential action from over 2000 local prosecutors and would impair the functionality of the presidential office: "Respect for the structure of government created by the Constitution demands greater protection for an institution that is vital to the nation's safety and well-being.

Chief Justice Roberts gave the lower courts a list of four considerations to determine when a congressional subpoena is appropriate within the scope of the separation of powers.

[33] The appeals court ruled unanimously on October 7, 2020, to deny Trump's objection and ordered the subpoena to be obeyed.

Trump had stated his intent to appeal that ruling to the Supreme Court and was granted 12 days in which to do so and prosecutors delayed execution of the subpoena.