If Florida's state legislature calls for a constitutional convention must the voters approve of calling the convention?

Yes and No. A Constitutional Convention, as defined by Article V of the U.S. Constitution, involves the legislatures of two thirds of the states calling for the Convention, as representatives of the people. The Convention maintains a republican-federalist quality, not direct democracy involving the sovereign.

However, one of the grievous defects of the constitution is the functional impossibility of amending the Constitution with regard to anything truly significant. Interestingly, Sanford Levinson argues that "the strictures (and structures) of Article V are limits on the agents of the people rather than on the general citizenry itself (or ourselves)." We should assert the sovereignty announced in the Preamble to "ordain and establish" a constitution -- which would be a "Yes" to your question.

Note the precedence from the framers ignoring Rhode Island and Article XIII, and establishing that a new convention could legitimately "declare that its handiwork would be binding if ratified in a national referendum where each voter had equal power."

Good Constitutional critiques include, Sanford Levinson's Our Undemocratic Constitution: Where the Constitution Goes Wrong (And How We the People Can Correct It) (2008) and Robert Dahl's How Democratic is the American Constitution (2003).

Go Vermont! Freedom & Unity!