Men try to conceal their liaisons, not advertise them, and when they fail, their reward is ridicule from Leno and Letterman, not the respect of a nation. Perhaps the political process selects rapscallions who thrill at defying the conventions that govern the rest of us. Or perhaps, as Henry Kissinger said, power is an aphrodisiac. But the simplest explanation may be that our leaders and celebrities show ordinary male appetites in extraordinary circumstances.
Most human drives have ancient Darwinian rationales.
Sexual desire is no different. A prehistoric man who slept with fifty women could have sired fifty children, and would have been more likely to have had descendants, who inherited his tastes. A woman who slept with fifty men would have had no more descendants than a woman who slept with one. Indeed, in all societies known to ethnography, it is the males who seduce, proposition, hire prostitutes, and accumulate spouses. On several college campuses, researchers have hired attractive assistants to approach students of the opposite sex and proposition them out of the blue.