Richard John Santorum is a former United States Senator from the Commonwealth of Pennsylvania. Santorum is a member of the Republican Party and was the chairman of the Senate Republican Conference, the number-three job in the party leadership of the Senate.

Santorum is usually considered a strong social and fiscal conservative but paleoconservatives and paleolibertarians have accused him of being too reliant upon the federal government. He also holds strong neoconservative stances in regard to foreign policy, which has further alienated many conservatives of a more traditional nature. He is particularly known for his stances on the U.S. invasion of Iraq, Social Security, intelligent design, homosexuality, and the Terri Schiavo case. Santorum was defeated 59% to 41% in the 2006 U.S. Senate election by Democratic candidate Bob Casey, Jr. This was the largest margin of defeat for an incumbent Senator since 1980. It is also the worst defeat for an incumbent Senator since Pennsylvania began direct senate election in 1918