Republicans held both US Senate seats from 1968 to 1991. In 1991, after the death of Senator John Heinz, a special election was held. In the election, former Kennedy administration official and Democrat Harris Wofford defeated former governor Dick Thornburgh, who resigned as President Bush's Attorney General to run in the election. The Republican defeat was considered to be a major upset. Wofford went on to be defeated in his bid for a full six-year term in 1994 by Congressman Rick Santorum. Republicans would hold both of Pennsylvania's Senate seats until Santorum was defeated in his bid for a third term in 2006.