In my lifetime it would have to be FDR, the bringer of socialism to America. After him it's Carter without a doubt -- the America-loathing enabler of Communism and Islamofascism. But it's hard to determine the long-range effects of Clinton's failure to block Osama when he could, and his administration's leakage of military secrets to the Red Chinese. Those things may have worse long-term effects than Carter's cluelessness. They all have one thing in common: they're Democrats.
This pops up every now and again, even though Willie took an ineffective shot or two at him.
How's come no one gives a rat's ass that George has totally ignored OBL for four years AFTER he did his best to annihilate the southern end of Manhattan island?
Whatever his faults, I give FDR credit for the fact that you are not speaking German and I (an American Jew) am alive.