MELBOURNE, Fla. -

President Barack Obama is unleashing a new Medicare offensive against rival Mitt Romney, eager to shake his Republican challenger off his economic focus and turn the campaign to territory more favorable to Democrats.

Campaigning for a second day in Florida, where older voters and workers approaching retirement hold sway, Obama on Sunday was expected to highlight a study by a Democratic leaning group that concluded that on average a person who qualifies for Medicare in 2030, today's 48-year-old, would see an increase of $124,600 in Medicare costs over their retirement period.

The study was conducted by David Cutler, a Harvard professor and health policy expert who served in the Clinton administration and was Obama's top health care adviser during the 2008 presidential campaign.