Florida is a closed primary election state. Only voters who are registered members of political parties may vote for respective party candidates or nominees for an office in a primary election including a presidential preference primary election.
However, there are times when all registered voters can vote in a primary election, regardless of which major or minor political party they are registered or even if they are registered without a specific party affiliation:
At a general election, all registered voters receive the same ballot and may vote for any candidate or question on the ballot. If there are write-in candidates who have qualified for a particular office, a space will be left on the ballot where their name can be written.