(L to R) Carter Phillips and Virginia Seitz, Sidley Austin (Photo: Courtesy Photo)

Sidley Austin is officially diving into the House’s legal battles.

Three attorneys at the law firm—Virginia Seitz, Carter Phillips and Joseph Guerra—filed notices of appearance as attorneys for the House in the Sierra Club and American Civil Liberties Union’s lawsuit challenging the Trump administration’s diversion of military funds for border wall construction. A short time later, they filed an amicus brief in the case on behalf of the House, marking Sidley’s first substantive filing on the merits of the case in the congressional legal battle.

Sidley was on a July 19 amicus brief the House filed at the U.S. Supreme Court regarding a stay issued in the U.S. Court of Appeals for the Ninth Circuit against Trump’s initiative. In that brief, House general counsel Douglas Letter was counsel of record.

Phillips and Seitz also entered an appearance as co-counsel in July for the House in its appeal in a similar case playing out in the D.C. Circuit. The firm and the House have yet to file their opening brief there.

In Monday’s amicus brief filed with the Ninth Circuit, the House’s lawyers wrote that Trump “is brazenly spending more money than Congress appropriated for construction of a southern border wall, in clear violation of the Appropriations Clause.” Sidley attorney Christopher Eiswerth was also listed on the brief, but did not file a notice of appearance.

“At bottom, the Administration claims that, even when Congress makes absolutely clear that it is limiting funds, the Executive can defy that limit with impunity, as long as it asserts that there is some statutory basis for spending money Congress unequivocally refused to appropriate,” they wrote. “Courts are empowered to enforce constitutional limits on the Executive Branch, particularly one of the most important checks the Founders adopted.”

U.S. District Judge Haywood Gilliam Jr. of the Northern District of California found May 24 that the administration had likely overstepped its statutory authority in allocating funds for construction between federal agencies. His injunction was overturned by the U.S. Supreme Court while the case was appealed to the Ninth Circuit.

Then on June 3, U.S. District Judge Trevor McFadden of the District of Columbia found that the House doesn’t have standing to sue the Trump administration over plans to redirect government funds to build a wall on the nation’s border with Mexico. McFadden called the issue a “close question,” and noted that he was not implying that Congress may never sue the executive branch to protect its powers.

The House passed a resolution earlier this year that allows Letter to turn to outside counsel to assist with his office’s myriad legal fights.

Letter has already tapped former U.S. Solicitor General Don Verrilli and his firm Munger, Tolles & Olson to help defend the Affordable Care Act in the case being weighed by the Fifth Circuit.

And he has involved Georgetown Law’s Institute for Constitutional Advocacy and Protection in several other cases, including litigation over the attempt to add a citizenship question to the 2020 census and the lawsuit seeking to compel testimony from former White House counsel Don McGahn.

Letter’s office is currently involved in roughly a dozen lawsuits, as House Democrats pursue a series of investigations into President Donald Trump, his family and his administration as they weigh whether to formally start impeachment proceedings.

Trump has promised to fight every subpoena, all but guaranteeing a legal battle over any disputed requests for information or testimony.

Seitz served in the Justice Department’s Office of Legal Counsel from 2011 to 2013, and returned to Sidley in 2014. She and Phillips are both partners for Sidley’s Supreme Court and appellate practice.

Guerra co-leads the firm’s Supreme Court practice, and also worked in OLC from 1999 through 2001.

Seitz, Phillips and Guerra all did not immediately return requests for comment.

Read the House’s amicus brief:

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