In a recent legal decision, a federal judge has determined that former President Donald Trump’s attempt to impose a requirement for documentary proof of citizenship on the federal voter registration form is unenforceable.

Presiding in Washington, D.C., U.S. District Judge Colleen Kollar-Kotelly ruled in favor of Democratic and civil rights organizations that challenged the Trump administration’s executive order aimed at revamping U.S. elections.

Judge Kollar-Kotelly found that the citizenship proof directive was unconstitutional, violating the separation of powers. This ruling represents a setback for the administration and its supporters who had contended that such a requirement was crucial to ensure that only U.S. citizens participate in elections.

In her opinion, Kollar-Kotelly stated, “The Constitution designates the responsibility for election regulation to the States and Congress, indicating that the President does not have the authority to mandate these changes.”

She further clarified that, concerning the setting of voting qualifications and the regulation of federal election procedures, the Constitution does not grant the President a direct role in either area.

Kollar-Kotelly echoed comments she made when she granted a preliminary injunction over the issue.

The ruling grants the plaintiffs a partial summary judgment that prohibits the proof-of-citizenship requirement from going into effect. It says the U.S. Election Assistance Commission, which has been considering adding the requirement to the federal voter form, is permanently barred from taking action to do so.

A message seeking comment from the White House was not immediately returned.

The lawsuit brought by the DNC and various civil rights groups will continue to play out to allow the judge to consider other challenges to Trump’s order. That includes a requirement that all mailed ballots be received, rather than just postmarked, by Election Day.

Other lawsuits against Trump’s election executive order are ongoing.

In early April, 19 Democratic state attorneys general asked a separate federal court to reject Trump’s executive order. Washington and Oregon, where virtually all voting is done with mailed ballots, followed with their own lawsuit against the order.