The full U.S. Court of Appeals for the D.C. Circuit will reconsider the dismissal of two lawsuits brought by House Democrats to enforce a congressional subpoena for President Trump’s former White House counsel Donald McGahn and to challenge funding for the president’s border wall.

The court’s decision marks at least a temporary victory for House Democrats and Speaker Nancy Pelosi (D-Calif.) over the weighty question of whether the judiciary has authority to resolve the separation-of-powers disputes between the White House and Congress. Any outcome, to be decided after an April 28 hearing, will likely be appealed to the U.S. Supreme Court.

Both cases concern the common question of whether the House has legal standing to sue the president. In one case, the House wants to check the president for allegedly overstepping his power by diverting billions intended for other purposes to pay for the border wall. In the other case, the House seeks to enforce oversight through investigation and impeachment by demanding testimony or information from the executive branch.

In rehearing the McGahn case, the circuit court also overturned a three-judge panel’s ruling Feb. 28 that Congress cannot sue to compel testimony by White House aides.

In a two-page order issued shortly before 5 p.m. Friday, the D.C. Circuit announced a majority of nine judges voted to vacate and reconsider the 2-to-1 ruling that McGahn can defy the subpoena issued by the House Judiciary Committee in its impeachment inquiry. Two other circuit judges, both Trump appointees who served in his administration, did not participate in the decision.

In McGahn’s case, a split three-judge panel agreed with the Justice Department argument that courts should stay out of political disputes between the two elected branches of government.

Writing for the majority, Judge Thomas B. Griffith wrote that courts “cannot decide this case without declaring the actions of one or the other unconstitutional, and ‘occasions for constitutional confrontation … should be avoided whenever possible.’ ”

In dissent, Judge Judith W. Rogers said the high court has long recognized Congress’s power to investigate and subpoena information, and warned the ruling undermines legislative oversight. She noted Trump’s “sweeping categorical resistance” and refusal to cooperate with the House impeachment inquiry.

The court’s opinion, she wrote, “all but assures future presidential stonewalling of Congress, and further impairs the House’s ability to perform its constitutional duties.”

Ordering McGahn to appear before the committee, she wrote, does not require the court to choose sides because the subpoena is not a demand for McGahn to answer specific questions — only to appear in person.

The third judge on the panel, Karen LeCraft Henderson, agreed with Griffith’s overall judgment but rejected a Trump administration claim that top White House aides enjoy “absolute immunity” from compelled testimony.

House Democrats went to court last year after Trump blocked McGahn’s testimony, saying the key presidential adviser could not be forced to answer questions or turn over documents.

The House committee subpoenaed McGahn in August before the start of formal impeachment proceedings that focused on Trump’s actions regarding Ukraine. Lawmakers said McGahn was the “most important” witness on the question of whether Trump obstructed justice in special counsel Robert S. Mueller III’s Russia investigation. McGahn left the White House in 2018.

Before Trump was acquitted in the Senate on Feb. 5, House lawyers said McGahn’s testimony was still critical to establish a pattern of alleged misconduct by the president.

McGahn was a key eyewitness to these events whom President Trump tried to enlist in this wrongdoing. President Trump has countered that McGahn is lying. The Committee must hear from McGahn directly,” the House argued in a 17-page appeal.

Blocking the McGahn subpoena, the House argued, is “sorely misguided” because it undermines Congress’s constitutional authority to check a president’s powers and encourages presidential stonewalling by future executives who can rest secure knowing that “direct, wide-scale noncompliance” is irremediable.

They argued the panel’s suggestion that the standoff was strictly a “political dispute” best resolved by regular checks and balances between the legislative and executive branches “downplayed the significance of its ruling.”

The accommodations process — by which both sides typically negotiate compliance with legislative oversight demands — “operates against the backstop of potential judicial enforcement,” the House warned. Remove that backstop, and Congress’s investigative power “is essentially meaningless.”

The circuit also agreed to rehear as a full court a House appeal of a lower court’s dismissal last June of its lawsuit to block spending on Trump’s plan to build a wall at the border with Mexico. The case was argued last month but remains pending before another three-judge panel.

At issue in the border wall case is whether the president’s diversion of funds to pay for the wall is an illegal act that violates the constitutional separation of powers between the branches of the government.

Ann E. Marimow contributed to this report.