In 1993 he was elected to the South Carolina legislature and in 1994 to the United States House of Representatives, where he quickly became powerful as a member of the Judiciary Committee during the impeachment attempt against president Bill Clinton in 1998. He opposed some articles, but vigorously supported others. In January and February of 1999, after two impeachment articles had been passed by the full house, he was one of the managers who brought the house's case to Clinton's trial in the senate. Though the Senate did not convict Clinton, Graham became nationally known.
He was reelected to the House in 1996, 1998 and 2000. In 2002, upon the retirement of the long-serving Strom Thurmond, the much younger Graham was nominated for the United States senate in 2002, and defeated his democratic opponent in his very important and closely-watched race.