Washington (CNN) A federal appeals court Friday severely limited Congress' ability to enforce subpoenas it sends to the executive branch, in a decision dismissing the US House of Representatives' lawsuit to force former White House counsel Don McGahn to testify.

In a 2-1 decision, the US Court of Appeals for the District of Columbia Circuit ruled it didn't have the constitutional authority to resolve the standoff between the House Judiciary Committee and the White House.

"We cannot decide this case without declaring the actions of one or the other [branches of government] unconstitutional," appellate Judge Thomas Griffith wrote in the opinion , determining the federal judiciary should stay out of the fight between Congress and the President. "If federal courts were to swoop in to rescue Congress whenever its constitutional tools failed, it would not just supplement the political process; it would replace that process with one in which unelected judges become the perpetual 'overseer[s]' of our elected officials. That is not the role of judges in our democracy, and that is why Article III compels us to dismiss this case."

The ruling is a major win for the Trump White House in its attempts to block administration officials from testifying to Congress.

If it withstands further appeals, the ruling also will have lasting reverberations across the federal government when the executive branch and Congress are at odds, as well as in the court system in Washington, which hears most major separation-of-powers disputes.

CNN legal contributor and law professor Stephen Vladeck said the decision would have "the effect of tilting power increasingly in favor of the recipients of such subpoenas, who can apparently defy them with impunity," and narrows Congress' power.

A spokeswoman from the Justice Department, which argued the case on McGahn's behalf, said in a statement Friday that the department was "extremely pleased" with the ruling.

"Suits like this one are without precedent in our nation's history and are inconsistent with the Constitution's design. The D.C. Circuit's cogent opinion affirms this fundamental principle," she said.

McGahn's private defense attorney declined to comment on Friday following the ruling. House Judiciary Chairman Jerry Nadler, a New York Democrat, said in a statement, "I strongly disagree with today's split decision. It is fundamentally hostile to reason and precedent, as the dissent recognized. If upheld, it would destroy the power of Congress to gather information and hold this or any future administration accountable. ... The House will now pursue an en banc rehearing of this decision."

House Speaker Nancy Pelosi noted that the ruling does not address the administration's claims of immunity for its current and former officials. "Today's split Court of Appeals ruling in the McGahn case does not contradict what the Courts have continued to rule: that the President's claims of 'absolute immunity' from Congress's subpoenas are false," the California Democrat said in a statement.

Griffith outlined the limits of the court system in separation-of-powers fights amid the government, noting that this case has created a "bitter political showdown."

He also noted that if the appeals court were to have ordered McGahn to testify, the ex-White House official likely would appear before Congress, then assert executive privilege. That would land the standoff back in court.

"The walk from the Capitol to our courthouse is a short one, and if we resolve this case today, we can expect Congress' lawyers to make the trip often," Griffith wrote.

Instead, the appeals court suggested the other branches of government should negotiate.

Griffith pointed to Congress' own weapons, including holding officers in contempt, withholding appropriations or refusing to confirm a President's nominees.

"Congress can wield these political weapons without dragging judges into the fray," Griffith wrote.

"Letting political fights play out in the political branches might seem messy or impractical, but democracy can be a messy business, and federal courts are ill-equipped to micromanage sprawling and evolving interbranch information disputes," he added.

Griffith was appointed by President George W. Bush. Judge Karen Henderson, who joined Griffith in the majority, was appointed by President George H.W. Bush. Judge Judith Rogers, an appointee of President Bill Clinton, dissented.

Rogers wrote that the court's decision on Friday will take away the incentive for the executive branch to negotiate with Congress.

"Future Presidents may direct widescale noncompliance with lawful Congressional inquiries, secure in the knowledge that Congress can do little to enforce a subpoena short of directing a Sergeant at Arms to physically arrest an Executive Branch officer," Rogers wrote. "By encouraging Presidential stonewalling, the court effectively dismantles the accommodation process."

The McGahn case, which started well before the House pursued impeaching the President over his pressure on Ukraine, had tested whether the White House could block its current and former officials from speaking to Congress.

The case was one of the most consequential to proceed through the courts during the President's impeachment inquiry and trial. During that proceeding, the White House had blocked several of its top officials from speaking to Congress in the same way it protected McGahn: by claiming absolute immunity from congressional testimony.

However, the appeals court on Friday didn't make a decision on the validity of the White House's sweeping claim of "absolutely immunity."

The House previously said it still wants to question McGahn about potentially obstructive behavior from the President toward the Russia investigation, which McGahn witnessed and had disclosed to former special counsel Robert Mueller over several interviews.

Friday's opinion could have immediate impact in several other ongoing court fights between Congress and the executive branch.

For instance, the appeals court's decision bodes badly for the House's pursuit of Trump's tax returns from the IRS -- making it likely that an early-stage lawsuit over the returns will get dismissed as well.

Judge Trevor McFadden had put a separate House lawsuit on hold over the request the Ways and Means Committee sent to the Treasury Department for copies of Trump's IRS tax returns, to wait for the appeals court to rule on its role in the McGahn standoff. The trial-level judge previously said the circuit court's decision regarding its role in deciding McGahn's case would affect what he does with the IRS lawsuit.

Minutes after the McGahn decision on Friday, McFadden scheduled a hearing in the tax returns case for next week.

The House's lawsuit against the IRS is separate from two tax-returns cases heading to the Supreme Court soon. In those, the House sought Trump financial records directly from banks and an accounting firm, and the Presidewnt sued to stop those service providers from handing over the records.

UPDATE: This story has been updated with statements from Reps. Nadler and Pelosi.