The NEPA has been used by President Donald Trump’s opponents in other legal battles to stall other projects supported by the Trump administration, including the immigrant detention center dubbed Alligator Alcatraz in south Florida. A federal judge earlier this year ordered the facility to be shuttered over a failure to conduct a proper environmental assessment under the NEPA, a ruling that was overruled by a federal appeals court weeks later.

FORMER OBAMA AND CLINTON LAWYER REPRESENTING LAWSUIT OVER TRUMP’S BALLROOM

The environmental assessment for the ballroom project claims that there is “no significant impact” to the White House’s environment, but the group says the assessment had a predetermined conclusion and does not adequately meet the NEPA’s requirements.

“This EA was facially deficient, internally contradictory, and plainly designed to support a predetermined conclusion,” the Monday court filing from the group reads. “The Defendants’ preparation and publication of the EA does not moot the National Trust’s NEPA claims. Indeed, the EA’s patent inadequacy makes it even more likely that the Trust will succeed on the merits.”

The filing claimed the environmental assessment “fails to acknowledge an additional significant impact in that the Ballroom Project will damage the Executive Mansion itself.”

The filing states the environmental assessments “are arbitrary and capricious because they fail to acknowledge this physical impact to the central White House structure as a significant impact in its own right, distinct from the impacts involving later-added (yet still historically significant) features. This impact would by itself trigger the need to prepare” an environmental impact statement.

In the White House ballroom case, the NTHP also renewed its arguments that the Trump administration’s decision to move forward with construction violates “numerous federal statutes, as well as the Constitution.” 

The Justice Department, in its previous filings, pointed to past additions and renovations to the White House at the direction of other presidents, arguing that Trump ordered the creation of a ballroom to meet a modern need, like other renovations. The administration also argued it was within its rights to demolish the former East Wing and build the new ballroom, further claiming that the group does not have standing to sue over the White House renovation.

The NTHP had asked U.S. District Judge Richard Leon to issue an emergency order to halt construction, a request he denied earlier this month, telling the group they failed to show harm during the likely time frame of the pause.

Leon instead ordered both the group and the Trump administration to file briefs ahead of another hearing on Jan. 15, 2026, with the DOJ’s response brief to the group’s Monday filing due on Jan. 8, 2026.

FEDERAL JUDGE UNLIKELY TO BLOCK WHITE HOUSE BALLROOM CONSTRUCTION

While Leon ruled in favor of the Trump administration during the hearing, he did warn that if anything is built underground that could affect what can be built above ground, the Trump administration “should be prepared to take it down depending on the Court’s resolution of the merits of this case.”

The proposed White House ballroom has been met with vocal uproar from Democrats and left-wing preservationist groups in the Washington area, while Trump has positioned it as his legacy project for the White House complex. In an earlier court filing, the administration revealed the ballroom is scheduled to be completed by summer 2028.