irreconcilable

The Irreconcilables were bitter opponents of the Treaty of Versailles in the United States in 1919. Specifically, the term refers to about 12 to 18 United States Senators, both Republicans and Democrats, who fought intensely to defeat the ratification of the treaty by the Senate in 1919. They succeeded, and the United States never ratified the Treaty of Versailles and never joined the League of Nations.