When most of the U.S. Court of Appeals for the D.C. Circuit hears arguments April 28 in a pair of U.S. House lawsuits, the judges may well be preparing to give the definitive answer on whether the chamber has the authority to sue executive branch officials.

The lawsuits over President Donald Trump's diversion of military funds for border wall construction and testimony from former White House counsel Donald McGahn initially captured attention over different legal questions they raised: Whether Congress is the only body that can appropriate funds, even under a national emergency declaration, and if an ex-White House official has "absolute immunity" from testifying before lawmakers, as Trump has claimed for McGahn.

But those arguments are no longer at the forefront, after a striking panel opinion was handed down in the McGahn case earlier this year that found the House cannot seek judicial review to enforce subpoenas. Judges Thomas Griffith and Karen LeCraft Henderson of the U.S. Court of Appeals for the D.C. circuit ruled against dissenting Judge Judith Rogers to find the House lacked Article III standing to obtain a court order enforcing a subpoena for McGahn's testimony.

In the prior year of House lawsuits, DOJ lawyers have repeatedly argued the cases don't belong in court. Most judges rejected those arguments, questioning how else the House can obtain relief in the face of persistent stonewalling by executive branch officials.

Irv Nathan, a former House general counsel, said it would be an "unmitigated disaster" if the House lost its ability to go to court.

"If the House is not able to enforce its subpoenas judicially, then it's going to be severely impaired in its ability to both oversee the executive branch and to get information necessary for legislation," said Nathan, who was general counsel during Nancy Pelosi's previous tenure as Speaker of the House.

Andrew Wright, a partner with K&L Gates who previously served as associate White House counsel during the Obama administration, said if the circuit goes in the Trump administration's favor, it could mean the House might start to lean on in its inherent contempt powers, which have fallen out of practice in recent decades.

Under those powers, lawmakers can direct the sergeant at arms to detain recalcitrant executive branch officials, or impose fines or other penalties on those who don't comply with congressional subpoenas.

"That could also really fundamentally alter how Congress deals with private sector actors. It's entire investigative system could become more coercive if the courts push them into that chute," Wright said.

Nathan echoed that concern, saying lawmakers being able to go to court is a "more refined and civilized" way of handling disputes between the branches, rather than inherent contempt. He said the latter "involves potential physical violence" and could result in "battles between the Secret Service and the congressional staff."

That's the same prospect that House lawyers have raised to the circuit. In a filing last week, the House team argued the system created under the original McGahn opinion "is one that leaves Congress effectively powerless to hold the executive accountable and would be unrecognizable to the Framers who designed our system of checks and balances."

The Justice Department argued in its own brief that Congress "lacks any inherent contempt power to arrest individuals for actions within the scope of their duties as executive officials," and should instead use political tools like withholding appropriations or blocking nominations to get officials to comply.

House general counsel Douglas Letter and deputy general counsel Megan Barbero, who both previously worked at the Justice Department, are set to argue against DOJ appellate attorney Hashim Mooppan on April 28.

The impact of the en banc circuit's ruling will be felt throughout the House's legal challenges. The McGahn panel opinion abruptly cast the other pending House lawsuits in a new light, as they largely hinge on enforcement of subpoenas seeking information from the administration under congressional oversight authorities.

Both U.S. District Judges Trevor McFadden and Randolph Moss of the District of Columbia have raised the panel opinion in McGahn in separate cases that also involve House subpoenas. McFadden, who ruled against the House's standing in the border wall case at the district court level, has stayed the House's lawsuit seeking Trump's federal tax returns pending the circuit's decision.

A D.C. Circuit panel also said last week it would not rule on a lawsuit from individual Democratic members of the House Oversight and Reform Committee seeking documents on foreign payments to Trump's D.C. hotel until the en banc ruling on McGahn lands.

The House has urged judges to not advance those cases until the en banc panel weighs in on the issue of standing. Justice Department attorneys say they don't mind waiting until that ruling comes out, but they want the U.S. Supreme Court to have final say, and a stay should last until the justices decide the matter.

Two other House lawsuits, over subpoenas issued to third parties, are already before the U.S. Supreme Court. The justices will hear those arguments via teleconference May 12.

The McGahn case has dominated the spotlight over the border wall case, which the House filed one year ago this month. It's one of several complaints filed in connection to Trump's declaration of a national emergency last year to tap Pentagon dollars for construction of a barrier at the southern border. McFadden, the trial judge in the tax returns lawsuit, dismissed it for a lack of standing last year, but noted in his opinion that it's a distinct legal question than that raised in subpoena lawsuits.

Both cases have also drawn in outside pro bono counsel: Jenner & Block and Georgetown's Institute for Constitutional Advocacy and Protection are helping the House on the McGahn case, while Sidley Austin lawyers are assisting on the border wall challenge.

The composition of the court could also play into the circuit's final ruling. Trump's two appointees to the circuit, Judges Neomi Rao and Gregory Katsas, are not sitting on the panel, presumably recused due to their contacts with McGahn while they worked together in the Trump administration.

That leaves just two Republican-appointed judges among the nine jurists sitting on the April 28 panel: Griffith and Henderson, who have already weighed in on the facts through their opinions in McGahn.

Wright said he's wary to weigh in on whether the politics of the president who appointed a particular judge plays a role in how they might rule on a matter. But he noted that Rao has made arguments in past opinions about the House's authorities—like investigations that could uncover negative information about an administration should only be conducted in the context of impeachment—that suggest she would also rule against the House in these cases.

Katsas, Rao and Henderson were the three judges on the circuit who said they would have granted a rehearing of a 2-1 panel decision that upheld a House subpoena to Trump's private accounting firm Mazars. Rao was the dissenting judge in that panel opinion.

The arguments will also be one of the first times the circuit will hear en banc arguments through teleconference. The House is just edged out from the first spot, as the circuit will hear a different en banc case one day prior.

The circuit had a rocky start to phone arguments, which began during the COVID-19 pandemic, but those that have taken place in the weeks since have gone more smoothly.

Read more: