Santorum trailed Casey in every public poll taken during the campaign. Casey's margin of victory (nearly 18% of those who voted) was the largest ever for a Democratic Senate nominee in Pennsylvania, the largest margin of victory for a Senate challenger in the 2006 elections, and the largest general election margin of defeat for an incumbent U.S. Senator since 1980. Casey was the first Pennsylvania Democrat to win a full term in the Senate since Joseph S. Clark Jr. in 1962.