Frankly, I don’t think the Dems need to steal an election in Pennsylvania. If Biden can turn out the Dem voting block, he will easily defeat Trump in Pennsylvania. Trump won here last time not because of some huge upsurge of pro-Trump votes, but because Hillary failed to turn out traditional Dem groups.
She did, and many voted for Trump. Trump needs to keep Philly as close as possible and he can do OK in Pittsburgh and take the state.