PHILADELPHIA — With about 48 hours until election day, Hillary Clinton's campaign and Democrats are stepping up their efforts in Pennsylvania as Donald Trump's campaign makes a late charge for the state's coveted 20 electoral votes.

In the final days, Clinton and her top surrogates are making trips to nail down the state. Clinton appeared Saturday night in West Philadelphia for a rally with music star Katy Perry, while President Obama and Michelle Obama are set to campaign alongside the former secretary of and former President Bill Clinton in their last rally Monday night on Independence Mall in Philadelphia.

Vice President Joe Biden is also spending his weekend barnstorming the state, holding events in fertile areas in an effort to get-out-the vote. A native of Scranton, Biden made the importance of Pennsylvania known during his opening remarks before a packed school gymnasium on Saturday afternoon, telling them that Pennsylvania, along with Bucks County, could determine the result of Tuesday's election.

"Here's the deal ... this election may very well come down to Pennsylvania, and it could literally come down to what happens in Bucks County," Biden said. "I really mean it. It matters a whole lot."

Democrats have dominated the state in presidential contests, having won every once since Bill Clinton took the state out of the GOP column in 1992. However, the state has been thrown into flux for the Democrats after the FBI revealed the re-examining of the investigation into Clinton's emails. Poll numbers have fallen sharply in the Keystone State for Clinton, who held a 6-point lead less than a week ago, which has turned into a slim 2.4-point advantage.

The Trump team, however, has made a concerted effort to swing the state into their column. Melania Trump gave her first speech since July's Republican National Convention on Thursday in Delaware County, one of the voter-rich "collar" counties that color the state red or blue. The GOP nominee himself rallied 12,000 supporters in Hershey on Friday night ahead of two more stops — Sunday and Monday rallies in Pittsburgh and Scranton, respectively.

While the top of the ticket contest has attracted most of the attention, the tighter race will likely be the state's Senate race between Sen. Pat Toomey and Katie McGinty, which has turned into a top target for both parties. Thus far, $140 million has been spent on ads, making it the most expensive race in the country.

Clinton and top surrogates have spent the past two weeks attacking the incumbent Republican, panning him for his inability to say whether he will vote for Trump on Tuesday. Biden did the honors on Saturday, but that hasn't deterred Toomey, who has become emboldened as the attacks pour in.

"I don't think so," Toomey told the Washington Examiner during a Friday campaign stop when asked if the attacks have dinged his chances. "I really don't. We think this is a tied race. I think this is a tied race. Our own research suggests that it's a tied race.

"If you look at the behavior on the other side. What have they done in the last couple of weeks? They have massively increased their spending," Toomey continued. "If they had this thing wrapped up, I guarantee you they'd be spending their own money somewhere else."

Rob Gleason, the state's GOP chairman, told the Examiner as much on Thursday, revealing that internal polling shows Toomey leading by 4 points over his Democratic challenger. He said that the same poll shows Trump trailing Clinton by only 2 points.

Some Democratic voters, however, fear that a Trump surge could sink Clinton on Tuesday, especially in the wake of the poor poll numbers.

"Yeah, of course I'm worried. It'll be a tragedy for America if it went the other way," said Jeffrey Ellis, 61, from Levittown who also attended the Biden event. "I try to be optimistic, but there's a little bit of a worry because Trump is such a bad face for America, if that were to occur. I trust and hope that she'll get in there."

"I'm hoping for her to win," said Kaitlyn Dadich, a 28-year-old Bristol, Pa., resident who attended Biden's event Saturday afternoon, Dadich admitted that she is "a little" worried about Tuesday's outcome.

"In this neighborhood, you see a lot of Trump signs, so it's tough. I don't know," Dadich said. "Now it's a close race and it's just really surreal to us that people could stand behind him."

Some top state Democrats, however, are still confident despite Clinton's slide in the polls. Josh Shapiro, the Democratic nominee for attorney general in the state, told the Examiner that there is still "great energy" and "great excitement" on the ground despite what the polls have showed over the past week.

"I'll just say I've been out in the community. I see the community's mobilizing. People are going to vote," said Josh Shapiro, the Democratic candidate for attorney general in the commonwealth. "There's sort of chatter that people aren't going to show up to vote. I think that's wrong. People are ready. They may be frustrated by some of the ads on TV, but they're ready for that to end."

"This is the great part of our democracy where everybody's equal on election day. Everybody gets one [vote]. No matter how much money you make, no matter how much of an insider you are, everybody gets one vote," Shapiro said. "It's the great equalizer in our democracy, and I'm confident in how things will turn out."