I consider Woodrow Wilson to be one of the two Presidents who injected the greatest quantity of slow-acting poisons into the political bloodstream of the United States of America. Unlike his competition for the "worst," Wilson was something of a proto-Obama insofar as absolutely nothing he did by design or accident was actually beneficial to the US.
JFK doesn't even come close to being the worst; moreover, he is now only runner-up in the category of "Most Media Sycophants."
Mr. niteowl77
Not to mention the League of Nations that begat the endearing United Nations that all the world suffers under.