What was once a comfortable lead in the polls for incumbent Sen. Arlen Specter over challenger Rep. Joe Sestak has evaporated; according to a new Qunnipiac poll out this week the race is too close to call.
Both campaigns made their final push before the vote Tuesday, with Specter and Sestak hitting the road to rally the base. Both men are hosted events in several cities this weekend. Specter kicked off with a rally in Philadelphia Saturday, while Sestak visited Pittsburgh and Erie.
Both candidates utilized traditional 11th hour strategies this week -- unveiling new ads and taking to the airwaves.
In an interview Thursday with ABC News' Top Line, Sestak said he believes these latest numbers reaffirm voters' desire for change.
"I think what you're seeing is just a group of people like me who say, 'Enough, Washington, you're broken,'" he said.
In a recent phone interview with ABC News, Sestak said that Pennsylvanians, "after being ripped apart by the recession, know that they cannot trust [Washington]. They want someone who would rather lose their job over what's right for them. It's time for someone who is in it for the people."
Specter's party switch in 2009 has received much attention in this primary. Sestak has said the former Republican's decision to turn Democrat was driven largely by Specter's personal motive to save his job. In an ad launched in the final two weeks of the campaign, Sestak highlights President George W. Bush's ardent support of Specter in his 2004 campaign.
Meanwhile, Specter unveiled two new ads of his own, featuring President Barack Obama and Vice President Joe Biden.
The Obama ad highlighted an earlier rally in Pennsylvania when the president reminded constituents that Specter "cast the deciding vote in the Recovery Act ... pulling America back from the brink."
Specter followed this with a new radio ad on Thursday, in which the vice president says Specter is "one of the most principled guys I have ever known."
Specter was unavailable for comment for this story.
While no one from the administration will be campaigning with Specter in the days before the primary, the ads are considered by many to be a benefit, given that Obama's approval ratings are significantly higher than those of Congress.
Sestak said he doesn't think the endorsements by Obama and Biden will be the deciding factor for Pennsylvania voters, even though Obama won the state in the 2008 general election.
"At the end of the day, no one from D.C. or Delaware will tell Pennsylvanians how to vote," he said. "Never have I gone into a VFW or a diner and been asked, 'Who endorsed you?' This is not the moment where anyone from D.C. is going to have an impact. They don't trust Washington. This is no longer a town of kings and king-makers." Indeed, in Senate races all across the country, strong party support and big endorsements don't seem to hold much sway with angry voters.
In Arkansas, Sen. Blanche Lincoln, a Democrat, is in a fight for her political life even though she is backed by President Obama. In Kentucky, Republican Trey Grayson is in trouble, despite backing from Senate Minority Leader Mitch McConnell, former Vice President Dick Cheney and former New York City Mayor Rudy Giuliani.
Many have cited Sen. Scott Brown's upset of Democratic candidate Martha Coakely in the January special election for the Massachusetts Senate seat of the late Ted Kennedy, partly out of concern that history might repeat itself in November if the Democrats are coming off a rough primary season.
But Sestak said a rigorous primary is good for Pennsylvania, pointing to the 2008 presidential primary season.
"This primary, as it did for Obama and [Hillary] Clinton, strengthens candidates. We're a hard, tough, smart crowd here in Pennsylvania. Going through this process helps you," he said. "It certainly helped me. It has taught me a lot."
Pennsylvania was considered a barometer for national sentiments in the 2008 Presidential election. Often considered a possible swing state, Pennsylvania holds a large middle class constituency, one that has felt lasting repercussions of the recession. Once a national leader in job creation, the state faces a 9.4 percent unemployment rate, in line with the national average.
Elsewhere in Pennsylvania is the first big test of Republican efforts to win back the House: a special election to replace long-time Democratic Rep. John Murtha, pitting Republican Tim Burns against Democrat Mark Critz.
Both parties brought out heavy-hitters. Bill Clinton stumped for Critz over the weekend; Scott Brown campaigned for Burns. Yet, as in the Senate Democratic primary, the race is also too close to call.
With the primary just days away, both Specter and Sestak will hit the ground in Pennsylvania, talking directly to the voters about jobs, about healthcare, and the host of issues that are central to their lives and their choice on the ballot.
Both candidates are campaigning hard until the very end, and have said they will remain in Pennsylvania through Tuesday's election results.
Come Wednesday morning, whoever wins starts the next battle, against Republican candidate Pat Toomey.
Quinnipiac polls puts Toomey ahead of Specter 47 percent to 40 percent. Against Sestak, the margin is 42 percent to 40 percent.