Douglas Letter, formerly one of the U.S. Justice Department's foremost appellate lawyers and now general counsel of the U.S. House of Representatives, will return to the U.S. Supreme Court lectern for the first time in 36 years to argue in the highest profile, political case of the term.

The Supreme Court on April 12 extended argument time in U.S. Department of Commerce v. New York, in which the Trump administration is defending its decision to place a citizenship question on the 2020 census.

Letter, whose motion for argument time was granted, will get 10 minutes of the 40 minutes accorded to the challengers, who include New York Solicitor General Barbara Underwood (20 minutes) and Dale Ho, director of the ACLU's voting rights project for the New York Immigration Council (10 minutes). They will face U.S. Solicitor General Noel Francisco (40 minutes).

In the space of roughly one year, Letter has moved from director of the Justice Department's civil appellate staff to a senior litigating position with an institute at Georgetown University Law Center to the House's general counsel office.

Doug Letter Douglas Letter, arguing in the Ninth Circuit in 2011. (Photo: C-SPAN)

In his most recent position, Letter is now at the center of some of the most contentious legal battles with the Trump administration, not just the census case but also the fight over the Affordable Care Act now pending before the U.S. Court of Appeals for the Fifth Circuit. He also is likely to be in the forefront of potential court subpoena fights over President Donald Trump's income taxes, the final report of Special Counsel Robert Mueller and more.

Letter made his only argument in the Supreme Court when he was 29 in the case United States v. Sells Engineering. He represented the United States.

Argued in March 1983, the question before the justices was under what conditions attorneys for the Justice Department's civil division, their paralegal and secretarial staff and all other necessary assistants, could get access to grand jury materials, compiled with the assistance and knowledge of other Justice Department attorneys, for the purpose of preparing and pursuing a civil suit.

Justice William Brennan, writing for a 5-4 majority, ruled against the government, holding that access was permissible only when the Government moves for court-ordered disclosure under Federal Rule of Criminal Procedure 6(e)(3)(C)(i) and makes the showing of particularized need required by the rule.

In his motion for argument time in the census case, Letter, joined by Hogan Lovells partner Neal Katyal and Georgetown's Institute for Constitutional Advocacy and Protection, told the justices that the House “has a paramount institutional interest and perspective in this case that merits granting it divided argument time.”

The lawyers added: “The decennial census is a vital cornerstone of our democratic institutions, and none more so than the House of Representatives. The House as a chamber depends upon an accurate census for its institutional integrity, and its membership will be affected by the outcome of this case.”