PHILADELPHIA — Every four years, certain states get to shine in the political spotlight because of the importance they play in the presidential election. Ohio, New York, Virginia and Florida have been fixtures on the list. But this year, one battleground state looms especially large.

“If either candidate wins Pennsylvania they have a tremendously high probability of winning the election,” said David Rothschild, an economist at Microsoft Research who runs PredictWise, an online forecasting model.

Pennsylvania — with 20 electoral votes — has been the most likely tipping-point state since midsummer, Rothschild said. If both candidates win their likely states, Pennsylvania will be the one that gets them to the magic number: 270 electoral votes.

In recent weeks, both campaigns have invested significant resources in the Keystone State, but Democratic nominee Hillary Clinton has held a narrow lead through the summer. A new Monmouth University poll released Tuesday showed Clinton leading 50 percent to 40 percent, driven by a surge in support among white women.

And the Clinton camp says it has no plans to slow down.

“Here in Pennsylvania, our campaign is running as though we’re 10 points behind, taking absolutely nothing for granted,” wrote state director Corey Dukes in a memo. “Since March, we have run the most aggressive, data-driven, coordinated campaign that Pennsylvania has ever seen.”

Last week, first lady Michelle Obama spoke on college campuses in Philadelphia and Pittsburgh, where she told students, “It’s not about voting for the perfect candidate.” And this week, Clinton held a family forum outside Philadelphia where revisited her rival’s weeklong battle with former Miss Universe Alicia Machado.

For a state that’s used to getting attention during election years, this time feels different, said Temple University political science professor Michael Hagen.

“Pennsylvania is a big prize and … it’s a place where they’ve been able to keep the race relatively close,” he said. “I’m not sure yet that it is in Clinton’s pocket. The race is still somewhat fluid [and] there will still be opportunities for things to swing back in the Trump direction.”

Despite concerted efforts by Donald Trump’s camp, the Republican nominee is losing support among white voters — a key constituency for him. The latest poll from Monmouth showed him trailing in support from women 55 percent to 35 percent; the group was evenly split just over a month ago. But the Republican nominee is not ready to give up, and some experts say he simply cannot.

“It’s hard to see Trump get to 270 without Pennsylvania,” said Matthew Levendusky, a political science professor at the University of Pennsylvania. “The challenge for the Trump campaign is that they have to almost run the table … they have to win all of these close swing states.”

While Trump does not release an extended schedule, four of his campaign’s eight planned events are in Pennsylvania. Trump campaign senior adviser David Urban said the campaign was “encouraged” by grass-roots support in the state and had all the resources necessary to win next month.

But Hagen said the campaign should be concerned by a widening gap in polls and needs to regain control of the narrative.

“The Trump campaign has lost control of the conversation for the past week or two and the focus has been very much on the negative side,” he said. “They’ve got to shift the focus back to the negative portion of Clinton.”

Last weekend, Trump drew headlines for his off-script remarks during an event in rural Manheim, where he accused Clinton of not being “loyal” to her husband, mocked her for feeling faint during a 9/11 memorial service and urged voters to “watch” certain polling stations in Pennsylvania on Election Day — a not-so-subtle suggestion the November election might be rigged.

Those comments have proven timely after a recent report from American cybersecurity firm Carbon Black warned about a potential computer hack. Most Pennsylvania counties use machines without a paper audit trail, leaving them at risk, cybersecurity expert Ben Johnson said.

Such an attack, or even the perception of one, would undermine our democratic process, he added.

“There’s always the possibility that whoever loses the election will claim potential outside interference,” Johnson wrote in an email.

The focus on interference, however, may simply signal awareness that time is running out for the candidates. With just 33 days left till the election, Clinton needs to maintain her lead while Trump needs to change the narrative.

“We’re passing the point of impact for ‘October Surprises,'” Rothschild said. “Donald Trump is in a very hard situation. He needs to swing a lot of movement and there just aren’t that many people left to swing.”

Published in conjunction with USA Today Logo