Pennsylvania has closed primaries. Senate Bill 357 would let independent voters choose which primary to vote in. According to this newspaper story, the bill has substantial support. So far it has not moved, and is in the Senate State Government Committee.
The newspaper story says the bill would set up an “open primary”, but that is not correct. “Open primary” has been defined in political science textbooks for over a century, and in U.S. Supreme Court opinions since 1972, as a system in which all voters may choose any party’s primary. Most southern states are open primary states. Typically, open primary states have a voter registration application that does not ask the applicant to choose a party, because there is no need for that information in an open primary system.
Here is the text of SB 357.