The United States of America functioned for nearly two centuries before it ratified a constitutional amendment dealing with presidential succession and the appointment of a vice president.

The 25th Amendment was ratified in February 1967. It came in reaction to the assassination of President Kennedy in 1963. The new president, Lyndon Johnson, served the remainder of JFK’s term without a vice president. LBJ got elected in 1964 and Hubert Humphrey joined the administration as vice president. President Truman took office in April 1945 after Franklin Roosevelt died just a month into his fourth term; Truman served nearly a full term, therefore, without a vice president.

The amendment has been used exactly once. Vice President Spiro Agnew resigned in 1973 and President Nixon appointed House Minority Leader Gerald Ford to become vice president. The new VP then settled into the Oval Office Big Chair when Nixon resigned in August 1974.

I mention this today because the 25th Amendment is getting some attention these days. It allows for a temporary replacement of the president if a majority of the Cabinet determines he is unable to continue doing his presidential duties.

Donald John Trump is in trouble. A special counsel is examining whether his campaign colluded with Russian hackers seeking to meddle in our 2016 election. There might be some issues relating to Trump’s myriad business holdings, too. Oh, and then the president declares that “both sides” were at fault in the Charlottesville riot, causing a serious rift between the White House and members of Congress of both political parties.

There have been some questions about the president state of mind, his ability to actually govern and, yes, his mental competence.

I’m not qualified to offer a psychological diagnosis, let alone from half a continent away. So I won’t go there.

The 25th Amendment is meant to ensure the executive branch continues to function even in these difficult times. Just how difficult will they become? I guess that depends on how the president responds to the mounting pressure.

I keep hearing about how angry he is getting. He’s been cutting people loose all over the place: national security adviser, gone; press secretary, gone; communications director, gone; chief of staff, gone; FBI director, gone; senior strategist, gone.

Trump popped off about neo-Nazis and Klansmen. The Joint Chiefs of Staff have effectively rebuked the commander in chief, although not by name. Congressional leaders are starting to weigh in. There might be some diehard Trumpkins among them, but the vast majority of public response has been highly critical.

Republican leaders are aghast. Never mind what Democrats think; it’s a given that they detest the president already.

In the meantime, the 25th Amendment looms as a serious talking point among the chattering class in Washington, D.C. Don’t for a single moment believe that the president is ignoring the chatter.