Judge Neomi Rao conceived a new concept of congressional authority in her dissent — one that extremely limits Congress, extraordinarily privileges the president and, if adopted, would overturn a long line of Supreme Court precedent.

The House, Rao said, cannot use its legislative power to target a president’s misconduct. It can only investigate whether he or she broke the law after invoking its impeachment power.

“Investigations of impeachable offenses simply are not, and never have been, within Congress’s legislative power,” Rao wrote, noting that “even a valid legislative purpose” would not justify an investigation. Under her approach, the judiciary has the power to quash an impeachment inquiry and “determine the scope of impeachable offenses.”

To the extent Congress launched an investigation purely to determine whether the president (or any other impeachable official) committed a crime, Rao is correct in her dissent. Congress’s oversight and legislative roles permit it to decide how to appropriately address concerns of illegality. It has a constitutional prerogative to initiate an impeachment inquiry, though there’s no precedent that compels Congress to forgo its legislative role when faced with a potential misconduct and limit itself to the impeachment process.

“The dissent would reorder the very structure of the Constitution,” said the opinion, written by Judge David S. Tatel and joined by Judge Patricia Millett, both of whom were appointed by Democratic presidents.

Rao, a former clerk for Supreme Court Justice Clarence Thomas and a Trump nominee who filled Justice Brett M. Kavanaugh’s seat on the D.C. Circuit when he was confirmed to the Supreme Court, adopted Trump’s argument that Congress issued the subpoena not to aid in weighing whether to enact new laws but merely as a pretext to investigate possible violations of existing ones; enforcing the subpoena, she said, would be likening Congress to “a roving inquisition over a coequal branch of government.”

However, the court’s majority found that the subpoena was “valid and enforceable” and the documents sought by Congress were relevant to determining the need for new legislation.

“Throughout history, the Constitution has left to Congress the judgment whether to commence the impeachment process,” Tatel wrote. “But the dissent’s approach would not even allow Congress to make the quintessentially legislative judgment that some concerns about potential misconduct or illegality are better addressed through oversight and legislation than impeachment.”

Tatel, a Bill Clinton appointee, continued: “We detect no inherent constitutional flaw in laws requiring Presidents to publicly disclose certain financial information. And that is enough.”

Friday’s decision is just the most recent in a series of lawsuits in which Trump has argued a broad claim of presidential immunity and suggested that a sitting president cannot be criminally investigated, ever. Now, with several matters still pending, the looming question is whether the Supreme Court will intervene — and, if it does, whether the justices will rely on Rao’s dissent as precedent.

The split at the D.C. Circuit has also divided the legal community.

“The decision [by Rao] is so totally wrong on the law and history that I don’t see it as being particularly useful,” Elizabeth Wydra, president of the Constitutional Accountability Center, a legal group that filed a brief in this case, told The Washington Post. “Following it would be an extraordinary step that would impact not only this president in continuing to act as if he’s above the law, but also on our constitutional system of checks and balances going forward.”

Experts who agree with Wydra called Rao’s dissent “whackadoodle” and “profoundly antidemocratic.” But others have described it as “thoughtful” and “not the hack-job Twitter would have you believe.”

In a piece published by The Post on Monday, Steve Vladeck, a professor at the University of Texas School of Law, said the opinion forewarned “the real constitutional crisis to come.”

Historically, “the unanimity of the court’s ruling made clear that compliance was the only available outcome,” Vladeck said, citing major civil rights cases and even the decision compelling Nixon to comply with the special prosecutor’s subpoena.

A court that speaks in unison is undoubtedly stronger. Rao’s dissent, Vladeck said, “raises the possibility that, were the court to reach the merits of one of these cases, at least some of the justices might be similarly inclined. Now, at least, such a vote wouldn’t be the first, and there’s a lengthy lower court opinion on which such a vote could rely.”