I have been sort of developing this theory on modern presidencies and how the successful ones have all been held by men with distant or completely absent fathers, while the failures were men who came from stable and prosperous upbringings.
Reagan's dad was a drunk and Clinton's dad died before he was born (and his stepfather was abusive), while Jimmy Carter's father was a successful businessman and member of the state House, George H.W. Bush's dad was a senator, and George W. Bush (who did at least serve two terms, although I can't think of anyone who is calling that a successful presidency-yet) was, you know, George H.W. Bush. Obviously this model works in Barack Obama's favor, but with all the bad breaks the guy has caught, who the hell knows?
As I say, it's just a theory. I have a feeling that if it holds up at all it has something to do with resilience and the ability to create your own narrative. Anyway, in researching this hypotheses to make it more plausible, I came across this, which seems to indicate that Jimmy Carter's father was actually Joe Kennedy. Which totally screws over my postulation. Back to the drawing board, I guess.