Republicans and Democrats also fought in court for months over the state’s voting rules, mostly resulting in the failure of GOP efforts to restrict mail voting.

Biden pulled ahead in the vote count in Pennsylvania, which has 20 electoral votes, on Friday morning as counties processed ballots cast by mail. Far more registered Democrats than Republicans used mail ballots to vote in Pennsylvania this year, according to data released by the state.

Biden centered his campaign in the state around Trump’s mishandling of the coronavirus pandemic and the economic ruin it has caused. He also touted his plans to expand health care, revive the manufacturing industry and direct the federal government to purchase goods in America, while attacking Trump for seeking to scrap the Affordable Care Act and threatening Social Security’s funding source.

Throughout the campaign, Biden made it a point to stump several times in areas outside of Philadelphia and Pittsburgh, the state’s two biggest urban centers — something Hillary Clinton was criticized for not doing enough in 2016. Biden also heavily outspent Trump in the state, including by a 3-to-1 margin on advertising in October and November.

Trump’s TV spots in Pennsylvania focused on claims that Biden would raise taxes on middle-class families, endanger Social Security and ban fracking, despite Biden’s promises to the contrary. Trump’s paid media made the case that he handled Covid-19 effectively and touted his foreign policy achievements.

But Trump himself rarely utilized the same strategies used by his ad-makers, straying from those talking points in recent speeches in Pennsylvania to downplay the virus and bash Democratic Gov. Tom Wolf. Trump also repeatedly singled out the state’s biggest city to scaremonger about election security: “Bad things happen in Philadelphia,” he said during a September debate.

Trump’s campaign long boasted about what it claimed was an unprecedented ground game, saying that it spent more than a year building its field operation and made nearly 13 million voter contacts in Pennsylvania. Following the outbreak of Covid-19, Biden’s team did not knock on voters’ doors in any state until October — a major gamble. In the closing days of the race, Trump’s aides said that would hobble the Biden campaign’s attempts to ensure that his supporters returned their mail ballots.

In 2016, Trump became the first Republican presidential nominee to win Pennsylvania since 1988, overcoming a deficit in the polls leading up to Election Day. This year, the race was remarkably steady, with Trump trailing Biden in virtually every poll for months.