Part of President Donald Trump's challenge to a New York state law that would allow Congress to obtain copies of his state tax returns should be dropped if a federal judge lets a New York state tax official out of the litigation, the New York Attorney General's Office argued this week.

Attorneys for New York state also made clear, in their filing to U.S. District Judge Carl Nichols of the District of Columbia, that Trump is a resident, and registered voter, of New York.

It's unclear, at this point, whether that will add weight to the state's motion to either have the lawsuit dismissed against State Tax Commissioner Michael Schmidt and New York Attorney General Letitia James, or at least transferred to federal court in Manhattan.

Patrick Strawbridge, an attorney representing Trump from Consovoy McCarthy, was hesitant to say whether Trump was a resident of the state during arguments on the motion last week. Nichols had posed the question to attorneys during the hearing.

"This might not even matter, but is Mr. Trump still a New York citizen?" Nichols asked. "A New York citizen attempting to sue New York defendants but doing all of that in D.C. is a little different than a D.C. citizen."

Attorneys for New York state appeared to consider the distinction an important one, according to their new filing this week. The New York Attorney General's Office wrote in the letter to Nichols that they searched for, and found, Trump on the state's voter rolls.

"Mr. Trump's voter registration status in this directory currently lists him as a registered voter under his Trump Tower address in Manhattan and indicates his voter status is 'active,'" the filing said.

But that point was more of an afterthought to the larger argument of the three-page letter: that a major part of Trump's lawsuit should be thrown out if Nichols allows Schmidt to exit the litigation.

Trump's attorneys are challenging the ability of Congress to take advantage of a New York state law, called the TRUST Act, that would allow certain committee chairpersons to request a copy of the president's state tax returns from the New York State Department of Taxation and Finance.

Schmidt is one of a handful of defendants on the suit, along with James, the House Ways and Means Committee, the committee's tax counsel, and Rep. Richard Neal, a Democrat from Massachusetts who chairs the committee.

There are two counts, or alleged statutory violations, to the lawsuit. The first alleged that Congress wouldn't be able to use the law, anyway, because the information would be about Trump's state taxes, which federal lawmakers don't regulate.

The second count claimed that lawmakers in New York passed the law solely to expose Trump's financial information for political gain. Trump's attorneys have said the law violates the First Amendment because it could be used to retaliate against the president for his political views.

Attorneys for New York argued in the filing to Nichols this week that if he grants their motion to take Schmidt off the lawsuit, the second count should be severed and tossed out.

That's because, they wrote, Trump wouldn't be able to challenge the constitutionality of the TRUST Act without Schmidt as a defendant. Because he's the state official who would disclose Trump's state taxes to Congress, he's the only party that could be sued to strike down the law, they wrote.

"Because it is the authority granted to the commissioner under the TRUST Act to provide Mr. Trump's state tax returns in response to a request that gives rise to the claimed injury," the filing said, "Mr. Trump cannot 'invalidate' that statutory authority by pursuing a claim only against the House Defendants in a proceeding where the commissioner is not a defendant at all."

To decide otherwise, attorneys for New York wrote, would be unreasonable as a matter of due process. If Trump is allowed to proceed on both counts without Schmidt as a defendant, that would presumably mean he could have filed the suit in one of several jurisdictions.

The TRUST Act allows the chairpersons of three congressional committees to make a request to New York for Trump's tax returns, as well as those of just about any other elected or appointed official in New York.

Attorneys for New York argued that, if Nichols agrees with Trump's attorneys, that would presumably mean the president could have also sued over the TRUST Act in jurisdictions where those federal lawmakers have district offices, like Massachusetts or Iowa.

"Under Mr. Trump's theory, he could bring suit in any of these jurisdictions, and obtain an adjudication on the constitutionality of the TRUST Act's grant of authority to the commissioner without the participation of the commissioner as a defendant, based on nothing more than the prospect that a request for New York tax returns might originate from there," the filing said.

Strawbridge did not immediately respond to a request for comment on the letter. Nichols did not indicate during the hearing last week when he was planning to hand down a decision on the motion.

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