I could remember that Carter was in the US Navy - turns out he had a pretty interesting career there - including being in charge of a team disassembling an onshore experimental reactor after a meltdown!
Yeah I recall him touring Three Mile Island not long after the accident. Carter is not lacking intelligence, but his political skills were certainly lacking and his presidency was pretty much a debacle.
http://en.wikipedia.org/wiki/Jimmy_Carter#Naval_career