(CNN) - Voters head to the polls for primary elections in Arizona, Vermont and Florida today in the most closely watched contests.
Former Florida governor Charlie Crist is expected to win the Democratic nomination as he tries to reclaim the job. Voters in Arizona will select a Republican candidate to run for the seat of retiring governor Jan Brewer. There's also a runoff for a house seat in Oklahoma.
Some of the primaries for House seats could affect the balance of power in the chamber next year.