Nate Silver reveals the one battleground state that could spell trouble for Kamala Harris

Polling and data guru Nate Silver warned Thursday that Vice President Kamala Harris is poised to be a "slight underdog" in Pennsylvania, which boasts 19 electoral votes and will likely determine the outcome of the presidential election.

Silver, a prominent elections analyst and statistician, wrote on Substack that while Harris is leading by 3.8 points in his national poll tracker and is slated to win the popular vote, his nuanced election forecast model predicts former President Trump is electorally favored to win the White House by a 52.4% chance, versus Harris, who now shows a 47.3% chance of pulling off an electoral victory.

"Kamala Harris had one of her worst days in some time in our forecast on Thursday despite gaining in our national polling average," Silver wrote.

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Democratic presidential candidate U.S. Vice President Kamala Harris speaks at a campaign rally on August 8, 2024 in Wayne, Michigan.   ((Photo by Andrew Harnik/Getty Images))

But, he continued, "There’s another, longer-term concern for Harris, though: it’s been a while since we’ve seen a poll showing her ahead in Pennsylvania, which is the tipping-point state more than a third of time in our model."

The latest Emerson College swing state poll shows Trump and Harris tied at 48% each in Pennsylvania. The Keystone State continues to see campaign trail traffic as both Trump and Harris battle for the largest electoral prize among the seven battleground states. Both campaigns have invested heavily in Pennsylvania, spending big bucks on ads and outreach.

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"The model puts a lot of weight on this recent data because of all the changes in the race," Silver explained. "And you can see why it thinks this is a problem for her: if she’s only tied in Pennsylvania now, during what should be one of her stronger polling periods, that implies being a slight underdog in November."

Former President Trump arrives to speak at a campaign rally on Friday, Aug. 9.  (AP/Rick Bowmer)

At the current date, Silver said his model shows a 17% chance that Harris wins the popular vote but not the Electoral College, calling it "a big concern for her campaign all along. 

"If she won the popular vote nationally by between 1 and 2 points, for instance, the model estimates that she’d still be a 70/30 underdog in the Electoral College," he wrote.

Still, Silver acknowledged that Harris' unusually late entry into the race could skew his forecast results.

"While there’s a solid basis for this empirically, you could argue we’re under unusual circumstances because of her late entry into the race. So if you want to treat all of this as a little fuzzier than usual, I don’t really mind that," he wrote.

Earlier this month, Silver said that Harris is slightly favored to win the presidential election if it were held then, but cautioned the public against relying too much on polls, citing their record of getting it "wrong" when it comes to former President Trump.

"If you have the election tomorrow… I think Harris would be a slight favorite," Silver said at the time. "She has been ahead in most recent polling in the ‘blue wall’ states, Pennsylvania, Wisconsin, Michigan, Georgia, North Carolina, Arizona, Nevada all polling in the margin of error range."

"People should remember, though, two things," he added. "One, we have three more months to go. There will be more surprises. And two, the polls have been wrong before. In both the last two general elections they underestimated Trump."

Yael Halon is a reporter for Fox News Digital. Story tips can be sent to This email address is being protected from spambots. You need JavaScript enabled to view it..