Even before polls open at 7 a.m. on Tuesday, the presidential battle in the Sunshine State is already almost half over.

Nearly 4.5 million Floridians voted ahead of Election Day, a total that represents almost 40 percent of the state's 12 million registered voters and half of those likely to vote.

The results of the early vote have not been announced, but officials do release the party affiliations of early voters. Democrats are leading  -- by a margin of 167,000 -- but that is a lower percentage of early voters than the party had in 2008.

Who ultimately wins Florida's 29 electoral votes still depends in large part on which party's supporters turn out in force on Tuesday, as well as who can win over more of the state's independent voters.