Incumbent: Republican Pat Toomey (retiring)
As an open seat that Biden carried last fall, Pennsylvania remains the seat most likely to flip in 2022 with Republican Sen. Pat Toomey not running for reelection. Democratic Lt. Gov. John Fetterman raised about $4 million in the first quarter -- an impressive haul for the first three months of the off-year. But the former Braddock mayor is still going to have competition for the Democratic nomination. He got a reminder of that late last month when the current mayor of the western Pennsylvania town endorsed one of his opponents, state Rep. Malcolm Kenyatta from Philadelphia, who raised just $374,000 in the first quarter. The field is still growing, with Montgomery County Commissioner Val Arkoosh launching her campaign earlier this month. Yet another Philadelphia politician, state Sen. Sharif Street, announced an exploratory committee, while members of the congressional delegation, like Reps. Conor Lamb, Chrissy Houlahan and Madeleine Dean, are eyeing the race, although they also have redistricting on their minds and would probably have to forgo reelection before knowing what their House districts look like in 2022. So far, it's mainly businessman Jeff Bartos running on the Republican side, who raised about $792,000 and loaned his campaign $400,000 in the first quarter, although current and former members of the congressional delegation could still join that contest too, as could several former Trump officials. While Democrats may be contending with a messy primary, they see the wide interest in the seat as a sign of the opportunity to flip it.