"As the Court reads it, presidential immunity would stretch to cover every phase of criminal proceedings", he wrote.
Mr. Trump sought to block a subpoena for his tax returns that state prosecutors sent to the accounting firm, saying it was unconstitutional to subject a sitting president to what he called the "criminal process".
Vance's office is specifically looking into whether NY state laws were broken when the president's lawyer, Michael Cohen, was reimbursed by the Trump Organization for payments made to adult film star Stormy Daniels, who claimed she had had an affair with Trump.
Trump had based his argument in part on the notion that a criminal investigation would hinder the performance of a President's duties to an unacceptable degree.
The case is Trump v. Vance, 19-cv-08694, U.S. District Court, Southern District of New York (Manhattan). Trump's lawyers immediately filed an appeal and an appeals court temporarily blocked the ruling. Justice Department policy has always been that sitting presidents can not be charged criminally.
The president has spent much of his almost three years in office shielding his tax returns from public view, and went against a four-decade precedent of releasing his tax information while running for office, as other candidates have since 1974 in the name of transparency.
The temporary stay expires on Wednesday, and the president's accounting firm, Mazars USA, has been ordered to begin delivering Trump tax returns to the Manhattan district attorney's office starting at 4:00 pm that day.
"Is this the witch hunt that the president says it is, or is it a legitimate prosecution run by the district attorney here in New York City?" he asked. The House of Representatives has subpoenaed six years of Trump's tax returns from the Treasury Department. Danny Frost, a spokesman for Vance, declined to comment.
Cohen is now serving three years in prison after admitting paying hush money - in violation of campaign finance laws - to Ms Daniels and another woman, tax fraud, and lying to Congress. The latter is likely what the founders had in mind for acts while in office, but nothing in the Constitution sets up that kind of immunity for potential criminal acts that took place outside of it. Lawyers from Vance's office told Marrero that NY law and legal ethics rules required them to keep he material secret. "The President provides no compelling proof that NY courts could fail to adequately adjudicate his immunity claim, relying instead on the unsubstantiated allegation that he would risk 'local prejudice, ' " the opinion states. Cohen said he and Weisselberg were both in Trump's office when Trump "directed us to go back to Weisselberg's office and figure this [the $130,000 payment to Daniels] all out".