Republican Governor Rick Scott, seeking re-election in a deadlocked race against Democrat Charlie Crist, was set to barnstorm Florida as polls open on Tuesday, with the outcome of the most expensive U.S. gubernatorial contest appearing to hinge on turnout.

From Miami to Pensacola, Scott planned to stump statewide as polls showed him in a dead heat against Crist, Florida's former Republican governor who is seeking the job back as a Democrat.

Both candidates were joined in recent days by national stars: Former President Bill Clinton campaigned for Crist, while Texas Governor Rick Perry and New Jersey Governor Chris Christie, both Republican heavyweights and possible 2016 presidential hopefuls, made appearances with Scott.

Almost half of Florida’s voters may have cast ballots before Election Day, according to the campaigns, which disputed who held the upper hand. Turnout may beat the 49 percent showing in 2010, when Scott won by 1 percent, or 61,000 votes.

Democrats, who have not won a governor's race in Florida in two decades, hope a ballot drive to approve medical marijuana will improve turnout by attracting young, liberal-leaning voters.

Neither candidate enjoys much love among voters, who have endured some 150,000 mostly negative television ads costing more than $81 million, according to the nonpartisan Center for Public Integrity, more than any other state-level races.

Spending in the race for Florida's governor outpaced even the fight for control of the U.S. Senate in most states, the report found, without including a final week ad blitz bolstered by nearly $13 million directly from Scott's personal fortune.

"Obviously this election isn't about picking the best and the brightest. It's about picking the candidate who is the least dangerous to Florida's quality of life," wrote Miami Herald columnist and popular author, Carl Hiaasen.

Crist accused Scott of being “out of touch” with working Floridians, citing Scott’s waterfront mansion and personal jet and reminding voters about the Medicare fraud scandal embroiling the hospital group co-founded by Scott, Columbia/HCA.

Republicans painted Crist as an opportunist who left the party to run unsuccessfully for the U.S. Senate as an independent in 2010, before becoming a Democrat in 2012.

The two candidates disagree on issues including same-sex marriage, medical marijuana, Cuba policy and raising the minimum wage. Their bickering extended to a podium cooling fan that delayed one of their televised debates, fodder for what pundits gleefully dubbed "Fangate" on social media.

Reuters