Florida isn't just a battleground state for presidential elections; it's ground zero in the nation's Obamacare wars. It's all about demographics. And geographics. Retiree-heavy Florida has a surplus of voting seniors nervous about Obamacare's changes. But Hispanics — the state's least-insured but fastest-growing population — tend to support the Affordable Care Act. The fourth-most populous in the nation, Florida is the most-diverse political swing state and has the nation's second-highest rate of the uninsured, nearly 25 percent. Active Democratic voters, who outnumber Republicans by more than 500,000, learned last year from President Obama's campaign that the law can be a political plus — especially among Hispanics — after it was a millstone in 2010.