Woodrow Wilson, 28th president
After World War I, Wilson traveled to Paris to take part in the peace treaty negations and to present his plans for a forerunner of the United Nations, called the League of Nations. But guess what? The US never became a member! Wilson made a critical error when he failed to invite any Congressional members of the Republican party to the negotiations. The party controlled both the Senate and House, and Wilson's snub helped to lead to the defeat of the proposal.