If the extra subsidies that help Americans pay for Obamacare insurance plans expire at the end of the year as expected, the most intense reverberations will be felt in South Florida, the country's top market for the coverage. As many as a third of the 4.7m Floridians on Affordable Care Act plans could drop them next year because of the higher costs. The state's demographics help explain its high demand for Obamacare: Florida is full of low-wage service and gig workers who cannot get insurance through their jobs and self-employed people. The biggest impact would be felt by older people at the lower edge of the middle class. Many people in their early 60s who earn around $65,000, for example, would experience a sharp increase in premiums " from a few hundred dollars a month to $1,000 or more.