Florida is a “closed primary” state. Although you are not required to declare a party preference, if you wish to vote in a partisan Primary Election, you must be a registered voter in the party for which the Primary is being held. For example only registered Republicans may vote for Republican candidates, and only registered Democrats may vote for Democratic candidates in a typical Primary Election.
There are exceptions. All registered voters are entitled to vote in a Primary Election in the following instances:
You can vote on ballot issues at any time.
You can vote for candidates in non partisan races such as Judges, School Board and City Council;
You can vote if the race is considered an “open” or “universal” Primary. This would be the case if there are no other candidates who have qualified to run in the General Election against the winner of a particular Primary race. This would mean that the winner of a particular race would automatically be elected to the position because he or she would face no opposition in the General Election. In this situation, all registered voters get to vote in the Primary race regardless of whether or not they have registered with a particular party affiliation.
A party change request cannot be accepted at the polling place on Election Day and be effective for that election. All party changes must be made by the end of the 29th day before the election ("Book Closing").