The longest ruling monarch in the history of the United Kingdom was George III, who was king for 60 years and considered “mad” during much of his reign. Through it all, Parliament ensured England’s endurance, notwithstanding its losing a portion of its colonial empire.

Nearly 250 years later, those former colonies are led by a president accused by members of his own administration of acting so erratically that they have on occasion surreptitiously stepped in to keep the country from falling into jeopardy. Yet, there is no reaction by Congress.

Is Donald Trump incapable of holding office, or is he the victim of an unelected cabal that has admitted to usurping the powers of a duly elected president to press an agenda it deems best for the American people?

The public deserves an answer. Congress has a duty to provide it.

The most damning accusation of Trump being mentally unstable was made in an anonymous opinion column published online Wednesday by The New York Times. “Meetings with him veer off topic and off the rails, he engages in repetitive rants, and his impulsiveness results in half-baked, ill-informed and occasionally reckless decisions that have to be walked back,” the commentary said.

The public should find comfort, the secret writer suggested, in knowing “senior officials in his own administration are working diligently from within to frustrate parts of his agenda and his worst inclinations.”

There’s no comfort in knowing the president isn’t really in charge.

Also released this week were excerpts from a new book by Washington Post reporter Bob Woodward, “Fear: Trump in the White House,” which said members of the administration would intervene when they thought Trump was acting erratically. Staffers said they would remove documents from his desk to stop Trump from issuing rash orders.

Though he now denies it, White House Chief of Staff John Kelly is quoted in Woodward’s book as saying of Trump: “He’s an idiot. It’s pointless to try to convince him of anything. He’s gone off the rails. We’re in Crazytown.”

Trump predictably turned to Twitter to respond to the double shot from Woodward’s book, which he called a “total piece of fiction,” and the Times commentary. Trump tweeted: “If the GUTLESS anonymous person does indeed exist, the Times must, for National Security purposes, turn him/her over to government at once!”

Trump’s accusers should come forward — not to be pilloried, but so the whole truth can be known.

The anonymous writer said there had been “whispers within the cabinet of invoking the 25th Amendment,” which details the process by which a president can be involuntarily removed from office. “But no one wanted to precipitate a constitutional crisis,” he said.

A crisis is exactly what this nation will have if the apparently well-intended White House “resistance” movement fails in its mission to thwart Trump’s “more misguided impulses until he is out of office.” An unintended or ill-conceived war is not out of the realm of possibility.

To be fair, Trump also has a right to know who his accusers are so he can directly answer questions about his stability.

The Constitution requires Congress to ultimately act on a president’s ability to serve. Removing a president would take a two-thirds majority in both houses acting in response to an appeal by the vice president and Cabinet. In other words, it’s a matter not to be taken lightly.

The 25th Amendment was enacted after John F. Kennedy was shot in 1963 to ensure a smooth process to transfer power should a president become incapacitated. No one then envisioned the provision being used to cloister a president accused of reckless behavior, though aides to President Ronald Reagan who observed him to be despondent years before he would be diagnosed with Alzheimer’s Disease briefly floated the idea.

Nor should the constitutional option be invoked now based solely on anecdotes from White House insiders.

It’s troubling that members of this “resistance” believe their “quiet” approach is justified by “bright spots” the administration has achieved, including “effective deregulation, historic tax reform, a more robust military.” Those clearly partisan achievements are no excuse for people who claim to be putting the country first not to stand up, show their faces and voice their concerns loudly and clearly if they believe Trump is too dangerous to be president.

A Republican Congress might be reluctant to act. But its duty is to the nation, not to any individual or political position. Our nation doesn’t have a king whose image must be protected because its Founders believed in rule by the people informed by truth. Let the truth about Trump be known.