The Democratic presidential candidate made the error during one of two rainy campaign demonstrations he made in the City of Brotherly Love on Sunday. And today, he came out in philly on election day with a megaphone and sounded barely audible.
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"I know Philadelphia well. I married a Philly girl, by the way," Biden told the crowd who had gathered in their cars outside the Sharon Baptist Church. "And by the way, I've got my Eagles jacket on."
Eagle-eyed Twitter users were swift to notice that Biden had mistaken, as his jacket actually showed a Blue Hen from University of Delaware, where he earned a degree in history and political science in 1965.
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Among those highlighting the mix-up was Zach Parkinson, the deputy director of communications for President Donald Trump's campaign, who wrote on Twitter: "This 'Eagles' jacket Biden claims he's wearing to try and show how much he's in touch with Pennsylvania? It's a Delaware Blue Hens jacket."
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During his talk, Biden implored with voters to turn out at the polls on Tuesday as he looks to increase support in Pennsylvania, which has surfaced as one of the most hotly-contested battleground states in the final days before the election.
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"We're at an inflection point. So we have to vote like we never did before. There's too much on the line to sit it out," he said.
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"We only have two more days. Two more days we can put an end to this presidency that has from the very beginning sought to divide us, to tear us apart."
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"Folks, in two days we can put an end to a presidency that has failed to protect this nation," Biden said.
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"In two days, we can put an end to a presidency that fans the flames of hate, poured gasoline on every opportunity he had all across this nation."
Biden has spent the final days of his campaign resonating with black communities to vote in-person during a pandemic that has disproportionately influenced their communities, suggesting that a strong turnout will boost his chances in states that could decide the election.
His first Philadelphia rally on Sunday was a "souls to the polls" event that is part of a nationwide effort to organize black churchgoers to vote.
"Every single day we're seeing race-based disparities in every aspect of this virus," he said, shouting to be heard over the blaring car horns.