ORLANDO, Fla. (AP) - The Interstate 4 corridor stretching from the Tampa Bay area through Orlando to Daytona Beach is a bellwether of the nation's largest swing state.

North Florida is predictably Republican, and South Florida remains strongly Democratic, leaving a swath of central Florida around Interstate 4 as Florida's primary battleground.The 6.5 million residents living around the 140-mile highway reflect the diversity of the state, and they account for a third of Florida's registered voters.More than a third of I-4 voters are registered Democrats, a third are registered Republicans and a quarter have no party affiliation.