State elections officials say Democrat Bob Casey and three Republicans filed petitions before Pennsylvania's deadline to get on the primary ballot for U.S. Senate.
The Republicans who filed by Tuesday night's deadline were U.S. Rep. Lou Barletta of Hazleton, state Rep. Jim Christiana of Beaver County and perennial candidate Joe Vodvarka of suburban Pittsburgh.
Barletta is endorsed by the state Republican Party and backed by President Donald Trump. He's in his fourth term representing a district that stretches from northeastern Pennsylvania to south-central Pennsylvania. Christiana is a fifth-term state representative.
Vodvarka is making his fourth run for U.S. Senate, but his first as a Republican. Former energy executive Paul Addis says he's ending his candidacy.
Casey is seeking a third six-year term. The Scranton native is the son of the former state governor.
The primary election is May 15.