The least passionate segment of Saturday night’s debate was a brief round on personal family values.

Without glancing at Gingrich, his adversaries gave toneless answers, citing their own long marriages and “character” as an issue, with only Rick Perry, suave as always, expanding on the subject:

“Not only did I make a vow to my wife, but I made a vow to God. That’s pretty heavy lifting. That’s even stronger than a handshake in Texas…If you cheat on your wife, you’ll cheat on your business partner.”

Gingrich, with a straight face, agreed that people should know “that this is a person that they can trust with the level of power we give to the presidency…I’ve made mistakes at times–I’m also a 68-year-old grandfather and I think people have to measure what I do now.”

Subject closed? Looking back at White House occupants since FDR, however, history suggest a more nuanced answer to the correlation between presidential performance and marital fidelity.

Truman, Nixon, Ford, Carter and the two Bushes (as far as we know) were faithful, although Carter during his campaign gratuitously told Playboy he had “looked at a lot of women with lust in my heart.”

Before and after being stricken by polio, Franklin D. Roosevelt was not. His romance with Lucy Mercer effectively ended the intimacy of his marriage to Eleanor and, in later years, Missy LeHand was his social secretary and “constant companion.”

When Eisenhower was president, there were rumors of an affair with his World War II driver, Kay Summersby, who after Ike’s death and shortly before her own, wrote a memoir about their relationship.

JFK and LBJ violated their vows early and often.

Sainted Ronald Reagan moved into the White House as the first divorced president, while Nancy worked tirelessly to remove all biographical references to his first Hollywood wife, Jane Wyman, who never spoke publicly about their marriage.

Bill Clinton’s “bimbo eruptions” and impeachment thereafter (by Gingrich) require no elaboration.

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