Republican Senate incumbent Rick Santorum and Democratic challenger Bob Casey are on the last leg of one of the most high-stakes Senate races in the nation.
The outcome of Tuesday's race, politicians and political experts say, will not only affect the balance of power in Congress but also influence policy leading up to the 2008 presidential election.
At a rally for his supporters last Saturday in Philadelphia, Santorum spoke of confronting terrorism as a "gathering storm of the twenty-first century," referring to a famous Winston Churchill speech from early in the World War II.
The war on terrorism - specifically the Iraq War - continues to be of one the primary issues that Santorum and Casey have addressed in their campaigns.
At a rally on Penn's campus Wednesday, Casey emphasized other concerns, such as tax cuts and education.
However, both candidates have spent significant time taking personal swings at one another, whether at live debates, rallies or in the numerous ads they have broadcast in television.
Democrats criticize Santorum's close voting record with President Bush, and, nationwide, Democratic candidates have run on the "we're not Bush" platform, according to Political Science professor Don Kettl, who spoke about the upcoming midterm elections at a round-table discussion over Homecoming weekend.
Republicans have countered that Casey shows little knowledge of the issues and refuses to take a firm position on anything.
Casey has enjoyed a consistent lead in the polls for months. Polls taken in the last week give him an advantage of 8 to 10 points, according to Pollster.com.
The race has been closely watched, as the Pennsylvania Senate seat is one of six that the Democrats would need to win to take over control of the upper house.
The midterm election is "setting up an enormous battle" for the 2008 presidential election, particularly regarding Iraq War strategy, Kettl said.
"The midterm elections are never about foreign policy - that is not the case this year, which demonstrates how much people are gearing up for 2008."
