A special election will be held Tuesday to replace Blaise Ingoglia, who resigned to become the state's Chief Financial Officer.
The Republican-only primary is for Senate District 11, which includes Citrus, Hernando, Sumter and parts of Pasco County.
The candidates are rancher Anthony Brice and former state Representative Doctor Ralph Massullo.
The winner will face off against Democrat Ash Marwah in the general election in December.
Voters can cast their ballots from 7 a.m. to 7 p.m. at their assigned polling place.
