Florida HB 1355, passed by the House on April 21, is 157 pages long. Among the changes is a provision that does not permit political parties to nominate anyone for any partisan office (other than president or presidential elector), if that person had been a registered member of another political party at any time during the year before filing to run for office.
The bill makes no exception for new parties. Therefore, a new party, formed in an election year, would not be permitted to have any nominees who had been members of another party for 18 months before the election. This part of the bill, if signed into law, would almost certainly be held unconstitutional. Similar laws in Oklahoma and Nevada were invalidated, as applied to new parties. The Oklahoma case was Crussel v Oklahoma State Election Board, 497 F Supp 646 (1980); the Nevada case was Long v Swackhamer, 538 P 2d 587 (1975). If a law like this had been in effect in 1854, the Republican Party would have been severely handicapped, because a great deal of Republicans elected that year had been Whigs or Democrats or Free Soilers immediately before the Republican Party was formed.
Courts in New Mexico and Colorado have ruled that it is unconstitutional for a state to tell a party that it can’t nominate a non-member. The Colorado case was Colorado Democratic Party v Meyer (1988); the New Mexico case was Woodruff v Herrera (2011).