Nina Khrushchev (left), the wife of Soviet leader Nikita Khrushchev, shakes hands with Jackie Kennedy in Vienna in 1961. (Central Press/Getty Images)

Still, he got a fine hand from the lunch crowd Friday at the JW Marriott hotel with a not-all-that-old joke. The lunch, to thank 150 or so mega-donors and including with various members of Congress and pals, was put on by Bill Marriott and Catherine Reynolds.

Romney started off by saying that people ask him all the time what, if he had won in November, he would be doing differently from Obama.

“That reminds me of a story,” he said, pitching a variant of a joke about someone asking a famous leader how world history would very different had Soviet Premier Nikita Khrushchev been assassinated in 1963 instead of John Kennedy.

(Various iterations have Richard Nixon asking this of Mao, someone asking this of Gore Vidal and a student asking this of the last head of the Soviet Union, Mikhail Gobachev, or of Soviet leader Leonid Brezhnev.)

The answer, always after much rumination, is that one can’t be sure, “But I don’t think Aristotle Onassis would have married Mrs. Khrushchev.”

We were told it brought down the house — a very friendly crowd indeed.