As the national early vote climbs past a staggering 93 million and challenges to the electoral process intensify across states, U.S. President Donald Trump and Joe Biden are barreling into Pennsylvania and turning it into the top battleground in Tuesday’s election, with Democrats flooding in with door-knockers and Republicans trying to parlay Trump’s rallies into big turnout once again.

​Both campaigns see Pennsylvania as increasingly crucial to victory: Trump now appears more competitive here than in Michigan and Wisconsin, two other key northern states he hopes to win, and Biden’s clearest electoral path to the White House runs through the state. Pennsylvania has more Electoral College votes, 20, than any other traditional battleground except Florida, and Trump won the state by less than 1 percentage point in 2016.

Trump devoted Saturday to four rallies across the state, and he and Biden planned campaign events for the final 48 hours of the race as well, with a wave of prominent Democrats and celebrities slated to arrive. On Monday, the president was set to make an appeal to white, working-class voters in Scranton, where Biden was born, while the Democratic nominee was aiming to solidify a broad coalition of white suburbanites and voters of color on a two-day swing through Philadelphia, Pittsburgh and elsewhere in western Pennsylvania.