While the story is that in California three quarters of the voters registered in the American Independent Party meant to register no party preference.
Here is the breakdown for party affiliation in Florida:
Data as of February 29, 2016.
COUNTY REPUBLICAN - DEMOCRAT - MINOR - NONE - TOTAL
Total 4,309,564 - 4,587,070 - 335,018 - 2,874,037 - 12,105,689
http://dos.myflorida.com/elections/data-statistics/voter-registration-statistics/voter-registration-monthly-reports/voter-registration-current-by-county/
"Minor" is for minor parties which are lumped together statewide. In different counties, different minor parties vary and there are many of them. The total percentage of minor party registrations is 0.00276.
The difference I am sure is not the intelligence of the voters - Florida's voter registration form lists:
Party Affiliation
(Check only one. If left blank, you will
be registered without party affiliation)
Florida Democratic Party
Republican Party of Florida
No party affiliation
Minor party (print party name)
________________________
http://dos.myflorida.com/media/693757/dsde39.pdf
Unlike California's voter registration form that lists minor parties along with the two major ones, Florida forces the voter to know the name of the minor party they wish to be affiliated with. Certainly that reduces the number of people registering in fringe parties and leads to less confusion. Since only the two major parties have primaries the system is rigged in their favor.
When I first registered to vote in the early 1970s only Democrats had primaries in Florida so pretty much everyone registered as a Democrat. Most state and local races were decided in the primaries since the Republicans did not have a foothold in most Florida counties. At that time Florida had its first Republican governor since Reconstruction, Claude Kirk, and he was despised by many.
How things have changed!