Obama is leading EVERY republican candidate at this moment. he WILL win florida
Incumbents always have the upper hand, if he was lossing in the polls now before the election has even begun then it would be a landslide for republicans.
Tampa is the convention site, Jeb bush may run, the state is gaining more old people and cubans who can turn into a huge anti-obama force since he has begun opening relations with cuba and has taken a rather weak foreign policy stance on...everything.
Florida is a toss-up at best for him
Florida is a must win for Republicans. It is not a must win for Democrats. Whether or not Obama will target it and to what extent depends on how much money he has compared to his opponent. If he has more he can afford to spend a lot in Florida, thereby forcing the Repblican candidate to spend money there, which obviously will make it harder for the Republican to compete in other swing states.