A political party is made up of individuals who organize to win elections, operate government, and influence public policy. The Democratic and Republican parties are currently the primary parties in Congress.
Learn more about political party divisions in the U.S. Senate.
In 1946, the Joint Committee on the Organization of Congress proposed that each house of Congress create party policy committees to develop a “unity of command” in Congress.
A History of the U.S. Senate Republican Policy Committee, 1947-1997 (GPO-govInfo) (pdf)