Two months ago, a three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit — the second-most-powerful court in the land — issued a ruling that would neuter Congress’ ability to investigate presidential wrongdoing. Two weeks later, the full court announced it would rehear the case. Nine D.C. Circuit judges finally heard oral arguments on Tuesday. They must not make the same mistake the three-judge panel did.

Though the implications are enormous, the specific issue is narrow: whether former White House counsel Donald McGahn must appear before the House Judiciary Committee, which issued a legal subpoena mandating his appearance almost one year ago to answer questions that emerged during the Russia investigation. The White House insisted McGahn was not required to appear, claiming he had absolute immunity from testifying as a former presidential aide. Though the courts have long enforced congressional subpoenas against various entities, the D.C. Circuit’s panel improperly ducked its responsibility to do so in this case, citing concerns about the judiciary wading into a political dispute of the sort typically settled by “flexible settlements” — give and take between the branches.

It is true that, in past years, under more reasonable leadership, such disputes between Congress and the president generally ended in some kind of compromise. Aides to President George W. Bush eventually gave transcribed interviews on the sudden firing of U.S. attorneys, for example. President Barack Obama eventually disclosed documents on the bungled Operation Fast and Furious. Each time, Congress initially obtained favorable federal district court rulings that helped lawmakers force compromise. Subsequent deals prevented higher courts from ever ruling definitively on how immune, if at all, executive branch officials are from congressional demands, so each branch preserved for another day its legal arguments claiming for itself maximum power or discretion.

President Donald Trump wrecked this tense balance by categorically refusing to comply with duly authorized congressional subpoenas, including the one issued to McGahn, and leaving no room for the usual negotiation. The D.C. Circuit panel that issued the court’s initial ruling worried about upsetting the equilibrium that had previously existed by siding definitively with the Judiciary Committee, ending the era of inter-branch compromise. But by staying out, the D.C. Circuit would in effect hand total victory to the president — also ending the era of inter-branch compromise, and with far worse consequences.

Ruling that Congress may not ask the courts to enforce its legal subpoenas would leave lawmakers with practically no options to conduct executive branch investigations. The White House would have little incentive to negotiate in the knowledge that it would face few or no penalties for stonewalling. The result would be far less legitimate oversight of the executive branch and far more comfort for rogue presidents.

We sympathize with the judges’ wish that the two sides find a reasonable settlement. In these circumstances, the only way to encourage that outcome would be to rule for the House in its legitimate effort to perform its constitutional function.

— The Washington Post