Lyndon Baines Johnson would fall asleep at night and imagine himself tied to the ground surrounded by thousands of voices, he once told Doris Kearns Goodwin. “They were all shouting at me and running toward me: ‘Coward! Traitor! Weakling!’ They kept coming closer. They began throwing stones.” Then he would awaken, “terribly shaken.”

This is the troubled man who withdrew from the presidential race. “Johnson gave you all of himself,” Norman Mailer once wrote. “He was a political animal.” He would be diminished as one, too — alone, at least politically.

Increasingly isolated, President Biden surely shared that agony when he made the decision to bow out of the 2024 presidential race. Perhaps, ultimately, he came to recall in assessing the race and his situation a fundamental principle of politics. “Politics is about tomorrow, not yesterday,” he told me in 2007.

With the years since showing, he must have accepted that he is yesterday and chose to let the party move on.

Most presidents look backward to find a way forward. They live amid portraits of George Washington and Abraham Lincoln. Rarely, but occasionally, they have found that there is no way forward. Not long before Johnson’s shocking announcement, he asked an aide for details on President Harry Truman’s 1952 declaration that he would not seek another term.

For Truman, like Johnson, the presidency had worn him thin. Truman’s wife had told him that she did not think either of them could survive four more years and urged him not to run.