An initiative is circulating in Florida for a top-two system. The initiative has already been endorsed by the Sun Sentinel and the Palm Beach Post. The reason for the endorsements is that the newspapers are concerned that independent voters cannot vote in most partisan primaries.
The newspaper editors don’t seem to realize that there are three better systems that would make it possible for independent voters to vote in primaries. Florida could have an open primary, which almost every other state in the south uses. In an open primary, any voter is free to choose any party’s primary ballot.
Or Florida could do as Louisiana has done, and abolish primaries. All candidates would run in November on a single ballot. Louisiana provides that if no one gets 50%, then a run-off is held in December (for state office, the timing is slightly different; the election is in October of odd years with any runoff in November).
Or Florida could provide for a blanket primary. In a blanket primary, all candidates run on the same primary ballot, and all voters use that primary ballot. Then, the top vote-getter from each party runs in November. Independent candidates can be handled in one of several ways. They could skip the primary and go on the general election ballot (California did that in regular elections in 1998 and 2000), or they could run in the primary and the general election (California did that for special elections 1967-2010), or they could run in the primary and be required to get at least 1% in order to run in the general election (Washington did that 1934-2000).
A blanket primary would be constitutional if the law provided that it was voluntary, and parties that didn’t want to use it could nominate by convention at their own expense.
Finally, any party in Florida is free to provide that independent voters can vote in their primaries, and there is some indication the Democratic Party is willing to do this. Parties are free to make this decision for themselves, no matter what the state law says. Parties won this freedom in a U.S. Supreme Court decision in 1986, Tashjian v Republican Party of Connecticut.