Congressman Pete King, the Republican chairman of the House Committee on Homeland Security, calls the scandal involving prostitutes in Colombia “the worst moment in the history of the Secret Service.”

He’s wrong about that. The worst moment in the history of the Secret Service was November 22, 1963, the day John F. Kennedy was shot and killed. It was the first and only time since the Secret Service was put fully in charge of protecting the president in 1902 that a president was assassinated.

Not that there aren’t certainly unfortunate similarities between the current situation and the events of 1963. William Manchester, in his 1967 book about the Kennedy assassination, The Death of the President, reports that nine agents of the White House Secret Service detail were out after midnight on November 22, starting with “beer and mixed drinks.” One agent was out until 5 a.m. Manchester wrote, “Fellow drinkers during those early morning hours included four agents who were to ride in the president’s follow-up care in Dallas, and whose alertness was vital to his safety.”

Clint Hill, the Secret Service agent in charge of Jacqueline Kennedy, writes in his well-timed new book that in the early morning of November 22, “the clock read almost 1:00 a.m., which meant by my body clock it was almost 2 a.m. East Coast time…We all walked over to the Press Club only to find the food was all gone. They had some peanuts, so I had a scotch and soda and some nuts.”

One of the ousted Secret Service supervisors in the current scandal reportedly posted a picture of himself guarding Sarah Palin and declaring that he was “checking her out.” Mr. Hill writes of Jacqueline Kennedy, “I always thought she looked so beautiful in her riding clothes — natural, no makeup, and after an exhilarating ride, her face was flushed from the exercise.”

The blame for Kennedy’s assassinations belongs not to the bodyguards but to the assassin. But it is worth remembering, too, that the Secret Service is an unusual creature. It was long part of the Treasury department, not the Justice or Defense departments, and it was originally created to combat counterfeit currency. To this day the service’s mission, in addition to protecting the president, is to “safeguard the nation’s financial infrastructure and payment systems to preserve the integrity of the economy.” When the federal government, in 2007, raided the Indiana office of Bernard von NotHaus, a manufacturer of copper and gold coins bearing the likeness of Ron Paul, it was the Secret Service that did the raiding.

It’s not clear whether lack of a presidential assassination in the years since 1963 is the result of luck, the excellence of the Service, or the ineptitude of would-be assassins. Whatever the reason, we should be thankful —political violence is an attack not only on politicians but on democracy itself. In Kennedy’s case, by the time the public found out about the early-morning carousing, it was too late.

The quote is attributed to Casey Stengel that it wasn’t sex that hurt his baseball players, it was staying up all night looking for it. For the Secret Service, the stakes are even higher than they were for the Mets or the Yankees. If the agents can’t go to bed at a reasonable hour the night before work, Congress may want to think about redistributing the responsibility for presidential protection to a different agency. The last thing we want is some present-day Secret Service agent, 50 years from now, cashing in with a book deal after years of battling what Mr. Hill calls “guilt, a feeling of failure, and a sense of responsibility for not being able to prevent the assassination.”

Ira Stoll is editor of FutureOfCapitalism.com and author of Samuel Adams: A Life.