Obama opens 3-point lead in Florida

Romney also led with NASCAR fans and military families; the president had the advantage with union households. The president's approval ratings in the state were evenly split, with 48 percent both approving and disapproving.

Florida's 29 electoral votes are likely a must-win for Romney; losing the state would require the Republican nominee to nearly sweep the remaining toss-up states. Obama won Florida 51 to 48 percent in 2008, but President George W. Bush took the state 52 to 47 percent over Sen. John Kerry in 2004.

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