President Donald Trump’s sprawling White House ballroom project just dodged another potentially devastating legal roadblock.

In a narrow 5-4 decision, the Supreme Court allowed construction of the new East Wing complex to continue while the Trump administration presses its appeal against a lower-court injunction.

The unsigned majority concluded that the National Trust for Historic Preservation likely lacks the legal standing necessary to challenge the project. The justices also found that halting construction could inflict “irreparable harm” on the government and interfere with critical security work.

That means crews can keep building the massive ballroom and underground military facility—even as the explosive fight over the project’s legality remains unresolved.

Trump wasted no time celebrating.

“The United States Supreme Court has just ruled, 5-4, that the magnificent Ballroom and Military Complex can continue, without any further contingency, doubt, or threat,” Trump wrote on Truth Social, according to Fox News.

“We are living in the Golden Age of America, and this Building will be one of the Greatest ever constructed in Washington, D.C.”

Trump said the project remains on track for completion in summer 2028 and predicted it will become “something that the entire Country is very proud of.”

He also insisted the ballroom is being financed entirely by private donors and corporations, calling it a “Gift” that will come at no cost to taxpayers.

Justices Cite Serious Security Concerns

The administration has argued that the ballroom cannot simply be separated from the fortified military installation being built beneath it.

In its ruling, the Supreme Court pointed to declarations from senior national-security officials—including the directors of the FBI, CIA, Secret Service and Office of the Director of National Intelligence—warning about the dangers of freezing construction midway through the project.

The Army secretary told the court that the planned ballroom’s height and mass are crucial to shielding the underground facility from potential attacks. Officials also warned that delays could disrupt Secret Service operations, expose the unfinished site to foreign intelligence gathering and create serious structural problems.

The majority stressed that it was not issuing a final ruling on whether Trump had the legal authority to undertake the project without congressional approval.

Instead, the court concluded that the National Trust’s lawsuit likely falters at the starting line because its alleged aesthetic and historical injuries do not amount to the concrete harm required to sue in federal court.

Roberts Breaks With Conservative Majority

The decision produced an extraordinary split, with Chief Justice John Roberts joining Justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson in dissent.

Roberts argued that the project is “likely unlawful” because federal law prohibits the construction of structures on government parkland in Washington without express authorization from Congress.

“The ballroom is a building or structure being erected on federal park grounds—President’s Park—in the District of Columbia,” Roberts wrote. “Yet Congress has not passed any law resembling ‘express authority’ for the Executive’s construction of it.”

Roberts accused the majority of allowing a likely infringement on Congress’ power over federal spending and property to continue.

“Today’s decision is no victory for the separation of powers,” he wrote.

The National Trust seized on that dissent while acknowledging the painful setback. President and CEO Brent Leggs said the organization was “deeply disappointed” but emphasized that the court did not decide whether the ballroom itself is legal.

“This is not the final decision on the merits of our case,” Leggs said in a statement.