Polls opened on Tuesday in the Florida primary election for the US Republican presidential candidate.
Mitt Romney had a sizeable lead over rival Newt Gingrich in most polls leading up to the vote.
Romney was ahead of Gingrich by 12 points in a Reuters/Ipsos poll on Sunday, and three other polls indicated his lead is between 11 and 15 points.
Should Romney prevail Tuesday, particularly by a large margin, it would revive questions of whether any candidate would be able to seriously challenge him, Gingrich included. Rick Santorum, former senator from Pennsylvania, and Texas Rep. Ron Paul are also running, but have trailed significantly in polls in Florida.