For President Joe Biden, who will hold a rare joint appearance with former President Barack Obama in Philadelphia meant to boost the Democratic candidate Lt. Gov. John Fetterman, Pennsylvania will amount to a political stress test in his home state, where he‘s traveled 20 times since taking office.

For former President Donald Trump, who rallies outside of Pittsburgh in the city of Latrobe, a win by his hand-selected candidate Dr. Mehmet Oz could prove his own enduring viability in a commonwealth he lost by a narrow margin in 2020.