Hillsborough may be Florida's number one swing county but regardless of what happens there, President Obama could lose the Sunshine State if he fails to get big numbers in South Florida.
In 2008, Obama got 529,000 votes from the big South Florida counties - Miami-Dade, Broward and Palm Beach. Half of those votes came from one county - Broward where Obama got 255,000 votes. Miami-Dade gave him 139,000 votes and Palm Beach 135,000 votes.
Obama defeated Republican John McCain by 237,000 votes statewide. If Obama's vote count in South Florida slips below 400,000 it will be a sign that he is in big trouble. In 2000, Al Gore got on 366,000 votes from those three counties. In 2004, John Kerry got 373,000 votes. Both men lost to George W. Bush.
Other counties to watch:
In 2008 Obama won Alachua by 27,000 votes, Orange by 87,000, Leon by 36,000 and Hillborough by 36,000. If those margins start to slip, Obama could lose the state.
For Mitt Romney watch these counties where McCain won. Romney will need to hold or improve on McCain's margins: Duval, 8,000 votes, Escambia, 30,000, Indian River 11,000, Martin 11,000, Marion 19,000, Santa Rosa, 36,000, St. Johns, 34,000, St. Lucie 15,000, Lee, 28,000.