Voters cast ballots in Florida primary election

Election features primaries for U.S. Senate

ORLANDO, Fla. – Nearly 2 million Floridians have already cast their ballots in this year's primary election, and others will head to the polls on Tuesday.

[FULL COVERAGE:  Residents 'shamed' into voting | Amendment 4 | Race results | Politics page]

Polls opened at 7 a.m. in Central Florida and will close at 7 p.m.

Turnout is expected to be high in many precincts.

In Orange County, more than 50,000 ballots were mailed in prior to Tuesday and more than 24,000 people voted early, according to Supervisor of Elections Bill Cowles.

Across Florida, eyes are on the U.S. Senate seat currently held by Marco Rubio. After a failed presidential bid, Rubio heads into the primary with a lead in the polls over his next closest opponent Carlos Beruff.

On the Democratic side, after receiving the backing of party leaders, Patrick Murphy aims to capitalize on a commanding lead over Florida U.S. Rep. Alan Grayson.

Dozens of other state and county races are also on Tuesday's ballot.

Volusia, Lake, Flagler, Osceola and Marion counties are voting on a sheriff.  Each race is a primary election, but a sheriff in Volusia County could be named if one candidate receives more than 50 percent of the votes.

In Orange and Osceola counties, the race for state attorney comes with some controversy. In early August, State Attorney Jeff Ashton raised ethical questions after he said a political action committee spent hundreds of thousands of dollars on his opponent, Aramis Ayala.

"This should be a serious concern to the voters of Central Florida who are electing the chief law enforcement officer of this circuit," Ashton said.

In a statement, Ayala responded to the Ashton's concerns.

"I accept the support of anyone who is dedicated to improving the criminal justice system for families in Orange and Osceola county," the statement read.

The Florida Division of Elections on Monday posted new totals that showed that nearly 536,000 voters cast their ballots during the early voting period that wrapped up this weekend. Another 1.15 million voters have voted by mail, bringing the total ballots cast to more than 1.69 million overall.

An additional 1.18 million ballots were requested but haven't been returned yet to election officials.

Florida has nearly 12.4 million registered voters and may surpass the voter turnout from the 2012 primary election. That year, 2.34 million voters cast ballots in the primary.