That court is also based in Manhattan.
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.
The president's lawyers appealed the judge's ruling to the 2nd U.S. Circuit Court of Appeals, which put the matter on hold while it considers the case on an expedited basis.
"The expansive notion of constitutional immunity invoked here to shield the President from judicial process would constitute an overreach of executive power", Marrero wrote. The president sued to block the subpoena, advancing a broad reading of immunity that Marrero described as "virtually limitless".
The judge wrote that the issues at hand stretched back to questions addressed by the Founding Fathers. According to Justice Department guidelines, federal prosecutors are barred from charging a sitting president with a crime, but the Constitution does not explicitly answer the issue, and the Supreme Court has never ruled definitively on the subject. Danny Frost, a spokesman for Vance, declined to comment. The court ordered Trump's legal team and lawyers from the Justice Department to file briefs by October 15.
"For those on Wall Street - and there were many - who believed that the judge was likely to defer to the judgment of the DOJ (and FCC), today's ruling should be a data point to rethink that view", said Levin, a former FCC chief of staff.
The state probe comes on the heels of a federal investigation into hush-money payments that concluded this summer.
While federal prosecutors have "effectively concluded" their investigation into the hush-money payment, Vance's office is exploring whether the reimbursements also violated any NY laws. Vance has said that, at this stage of the investigation, Trump "has not been identified as a defendant, nor is there an assumption he will be".
"That doesn't immunize him permanently", the president's attorney William Consovoy said in the filing. "Would those secrecy laws trump that subpoena?"
He said even President Richard Nixon had conceded during the Watergate scandal that he would be required to produce documents in response to a judicial subpoena. Trump's lawyers filed an immediate appeal, and the judge's order has been temporarily blocked as that process plays out. Trump's opponents have always been eager to get their hands on the president's tax returns but - breaking from a tradition followed by previous presidents - he has steadfastly refused.