Who was the worst president of the 20th century?

Thomas Ricks says it was JFK, largely for foreign policy reasons -- the debacle in Vietnam being the primary although not exclusive cause of JFK's poor standing in Rick's opinion. I think that JFK suffered from the curse of being president during interesting times, and while he made made mistakes and misjudgments in foreign policy, he was far from our nation's worst 20th century president.

My vote for worst president of the 20th century, for reasons involving both domestic and foreign policy, goes to Woodrow Wilson. Virtually all of the excesses of American policy in the 20th century built on demons that Wilson unleashed.