If you are going by incompetence, Buchanan. His ham fisted retarded 4th grader approach directly led to the civil war. If you are going by malfeasance, FDR hands down. The guy was seriously a fucking commie who stole money from people with the gold act, prolonged world war 2, let eastern Europe fall under the whip of Stalin, put loyal Americans in concentration camps, wiped his ass with the Constitution, started us on the slippery slope to economic tyranny, and he died in the arms of his side bitch while his wife was at home like the lying degenerate fuck that he was. Fuck him and everything that came from him.