In 1986, I published a novel, a parody White House memoir, that begins on Inauguration Day 1989 with the president-elect arriving at the White House to escort outgoing President Reagan to the Capitol for the ceremony. But Mr. Reagan won’t leave. Not for reasons of obduracy or to thwart the democratic process. He’s just gone a bit dotty. It’s cold outside, he’s still in his jammies, and he doesn’t feel like leaving. Maybe tomorrow.

That turned out to be a risqué premise in 1986. I remarked to an interviewer from The Washington Post that I worried I might have offended Mr. Reagan. Four days later, the U.S. Postal Service—not yet ruled by a presidential donor-crony—delivered a handwritten note from the president saying he was delighted by his part in my novel. That’s class. That was then.