CA used to have an open primary, too. In March 2002, we (in CA) had a "modified open primary" where decline-to-state voters could choose the partisan ballot of one party, provided that party allows nonmembers to vote in their elections.
Four parties, including the D and R, allowed nonmembers to vote for the elected office nominees but not for the parties' central committee members.
I think this decision by the 9th CCoA is correct, since political parties should not be required to have their nominees decided by nonmembers. But, I disagree with their decision about the CA recall.
Acutally, Califonia had an open primary ("cross-filing") in effect years ago. The open primary that the 9th struck down was a modern version of it. I remember 'cross-filing' back in the '50s. I think it went away in the '60s.