There are a shocking number of incumbent PA Senators facing a potential primary this year.
Dems facing primary challengers: Art Haywood (SD-04), Anthony Williams (SD-08), Lisa Boscola (SD-18), Marty Flynn (SD-22), Wayne Fontana (SD-42).
GOPers facing primary challengers: Lisa Baker (SD-20), Pat Stefano (SD-32), Camera Bartolotta (SD-46), Christ Gebhard (SD-48).
That is 9 of the 25 incumbents (no retirements on the senate side this year in the Keystone State) facing a challenger this May as it stands.
By my count, there are 30 state legislative incumbents facing a primary this year, per DoS data as of ~7:30 p.m . This could change due to new additions or petition challenges; and how many are serious is a separate q still. But that's the state of play.