Graham was elected to serve as a United States Senator on November 5, 2002. He serves on four committees in the U.S. Senate: Armed Services, Budget, Judiciary, and Veteran's Affairs. During the 108th Congress he served on the Health, Education, Labor, & Pensions Committee. He also served as the Chairman of the National Senatorial Committee's Presidential Roundtable from 2003-2005.

Graham was elected to four terms, begining in 1994, as the Congressman from South Carolina's Third District which includes the state's largest employer--the Savannah River Site. The district includes ten counties and runs along the western border of the state encompasing national forests and parks. He was the first Republican to represent the district since 1877. While representing the district he was a member of the Education and the Workforce, Judiciary, and Armed Services committees.

During his time in Washington Graham has become known as a leader who never abandoned his independence or strayed from the conservative reform agenda. He has fought to balance the federal budget, provide tax relief for all taxpayers, ensure our military is adequately funded and prepared, and ensure the government keeps its promise to America's greatest generation.

Prior to his time in Washington Graham served in the South Carolina State House representing the second district of Oconee County. Graham also held positions as the city attorney for the City of Central and the assistant county attorney for Oconee County.

Graham served six years active duty in the United States Air Force as a lawyer, including a stint at Rhein Mein Air Force Base in Germany. He then served for five years in the South Carolina National Guard. He is a Persian Gulf War-era veteran, who was call in to service state-side at McEntire Air National Guard Station as Staff Judge Advocate. In this capacity he prepared members for deployment to the Gulf region. His duties included briefing pilots on the law of armed conflict, preparing legal documents for deploying troops, and providing legal services for for family members of the South Carolina National Guard. He recieved a commendation medal for his service at McEntire.