Someone emailed an article to me about a claimed link between sociopathy and being an elected official. I don't know if there really is a link between public office and being a sociopath. Intuitively that would seem right, if for no other reason that just that it takes a certain personality type to want that kind of job in the first place. So let us assume that there is a link between sociopathy and public office and ask the next question: Is that a bad thing?
A president's job description is to deal with crooks and scoundrels, of both the congressional and the global political variety. We have an incredibly cumbersome political system in which even having the president's party control both houses of Congress is no guarantee that the president will get Congress to pass the legislation that he wants. Given those two realities, maybe sometimes being a sociopath is the only way to get something done. Part of the reason FDR was such an effective president is that he was so very adept at both using deception and abusing power.
Contrast FDR with the basically decent but woefully incompetent Jimmy Carter. Had our embassy in Iran been seized when FDR was in power, he would have turned Teheran into a moonscape; just ask the people of Dresden, a city FDR incinerated on far less provocation. Having defeated Iran militarily, he then would have given Iran a pro-Western government rather than permit the ayatollahs to plunge it back into the Middle Ages. Yes, people would have died but a clear message that it's not acceptable to seize an American embassy would have been delivered, and today, Iran might actually be a free society that doesn't threaten to destabalize the entire region.
Jimmy Carter, on the other hand, was so loathe to use the military that he preferred to allow the United States to be humiliated for 444 days. He was determined that no one would die, and he was also mindful that some of the Iranian's grievances against the United States had some merit. While that may give him points for being a decent human being, it's no way to run a government. Thirty years later, the emboldened ayatollahs are threatening the region with a nuclear weapons program, funding terrorism, and suppressing the civil liberties of their own people.
There is something to be said for being a decent human being. But given a choice between the decidedly ethically challenged FDR and the fine human being Jimmy Carter, I'll take FDR any day. We live in the world we actually live in, not the one we wish we lived in.