from wiki:
“The president with the longest retirement was Herbert Hoover, who died 11,553 days after leaving the presidency. Jimmy Carter currently has the second-longest retirement, and he will tie Hoover if he lives to September 7, 2012. The president with the shortest retirement was James K. Polk, who died 103 days after leaving the presidency.”
Interesting that they are both some of the worst presidents ever. Add johnson to the list and you have the 3 worst presidents in the last 150 years, imo. If obama loses this november, he will have a good shot at beating both hoover and carter for longest retirement.
But an absolute shoe-in for the "Worst President" ever. He will sky rocket to the top of the list!!!