The California Constitution, Article II, sec. 5(a), says, “The legislature shall provide for primary elections for partisan offices, including an open presidential primary whereby the candidates on the ballot are those found by the Secretary of State to be recognized candidates.”
The Independent Voters Project, which supports the top-two system, filed a lawsuit on July 23, 2019, arguing that because the term “open primary” is in the California Constitution in connection with the presidential primary, therefore the current law on presidential primaries (which allows each party to decide whether to let independent voters vote in its presidential primary) violates the California Constitution. The Independent Voters Project thinks “open primary” in this context means the state must print a presidential primary ballot with all presidential primary candidates from all parties on that ballot, and that any voter must be allowed to use that ballot.
The case has a hearing in San Bernardino on November 19 at 8:30 am. It is Boydston v Padilla, civ-ds-1921480.
That part of the California Constitution was added many years ago by the voters, and the Voters Pamphlet for that election shows that “open primary” meant a presidential primary open to all partisan candidates. Before that was added to the California Constitution, presidential candidates needed a severe petition in order to get on a presidential primary ballot.