Republican Sen. Rick Santorum is up for the fight of his life. First elected to the Senate in 1994, the conservative lawmaker is trailing his Democratic opponent, state Treasurer Bob Casey Jr., son of the late Gov. Robert P. Casey, by 13 percentage points. With the mud already flying, this race is proving to be one of the most hotly contested in the country. Democrats are hoping that Casey's opposition to both abortion and gun control will help win over enough conservative independents. The gubernatorial race is also on the ballot, which could potentially increase voter turnout and become the deciding factor on Election Day.