At this late hour, there is a chance—admittedly a very slim one—that Donald Trump might wish to avoid a catastrophic loss to Hillary Clinton, or that Republican leaders might petition him to step aside as their nominee. There is time enough yet for such a thing to happen, and there is a remote—a very remote—chance that it could happen. More pertinent, however, is the fact that this sequence of events is possible, and that there is precedent.

In late July 1972, shortly after the Democratic National Convention, it was revealed that George McGovern's vice-presidential running mate, Thomas Eagleton, had been hospitalized in the 1960s for depression, and undergone electroshock therapy. Whether this psycho-biographical fact would be a disqualifier today is an open question; but Eagleton had never mentioned it to McGovern, and in any case, he had been chosen after several other potential candidates had refused McGovern's offer. After a brief public controversy, featuring McGovern's famous pledge that he supported his running mate "a thousand percent," Eagleton resigned from the Democrat ticket.

In August, accordingly, the Democratic National Committee reassembled in Washington, and Sargent Shriver was chosen as Eagleton's successor. Of course, the matter had been resolved informally—once again, McGovern was obliged to offer the poisoned chalice to a long list of worthies—but members of the DNC had to ratify the decision in official session. The venue was a ballroom in the Sheraton Park (now Wardman Park) Hotel in Washington, and I was there.

Two spectacles stand out in my recollection. One is the fact that the hotel ballroom at the Sheraton Park was considerably smaller than the Miami Beach Convention Center, where the Democrats had met just weeks before, and I was impressed with the extent to which television coverage dominated the event. The ballroom floor was carpeted with cables, and people like me (a newspaper stringer/ex-DNC staffer) were continually admonished to shut up, or step aside, in order not to spoil interviews or camera angles.

The other spectacle was inadvertent. At some point, before the meeting got underway, I sought to proceed from point A to point B, and found myself backstage, more or less, traversing a series of Sheraton Park corridors. Suddenly, after a turn around one corner, I found myself alone in a hallway with none other than Senator Eagleton himself. He was pacing along the wall, fists clenched and unclenched, eyes blazing—and mumbling to himself.

Surprised, and embarrassed, I thought I had stumbled upon evidence of Eagleton's mental instability but now realize that he was probably rehearsing his remarks—and of course, under considerable strain. If he saw me, as he undoubtedly must have, he merely glanced in my direction, and I beat a hasty retreat. An hour later, or so, the torch was graciously passed from Eagleton to Shriver, and the Democrats pretended as if it were all business as usual.

In retrospect, the fact that the Secret Service had not shut down a perimeter of several city blocks, allowing a 22-year-old to wander around unchallenged, is almost as astonishing as the event itself.