The latest version of the Ryan plan gives some future beneficiaries the choice of using the voucher or keeping a more traditional Medicare program. Ryan’s plan would restructure Medicare for those younger than 55.

His Social Security plan would allow those younger than 55 to invest a part of their Social Security taxes in “personal retirement accounts” managed by the government, not private firms.

So the elderly wouldn’t be affected.

Obama has called Ryan’s plan “privatization” of Social Security, which it isn’t. But it does put Social Security on that path, and the line of attack helped sandbag President George W. Bush in 2005, when Ryan pushed him to adopt conservative reforms to Social Security, which provides about $49 billion in Florida and serves 3.7 million residents.

If nervous seniors can be convinced by Romney and Ryan that the plan doesn’t hurt them, their potential opposition could melt away. And if future retirees can be convinced that Medicare needs to be changed, then Democrats won’t have much of an attack.

Those are big ifs. Now the sell job — the policy campaign within the presidential campaign — begins.

About 17 percent of the state’s population is older than 65; seniors make up a disproportionately larger segment of the electorate.

Right now, about 3.4 million people directly benefit from Medicare in Florida, which receives about $25.2 billion from the program. Ryan and Romney also want to cap expenditures for Medicaid, a massive $21.4 billion state-federal program in Florida that accounts for a quarter of the state’s budget and has grown in the bad economy. About 3.3 million Floridians receive Medicaid.

At least in the short term, Ryan’s selection transforms the presidential campaign into a policy-heavy discussion.

Doubling down

A Romney-Ryan ticket doubles down on the idea that major entitlement programs can be overhauled and taxes can be cut — especially for the wealthy, whom they describe as “job creators.”

Obama, by contrast, has called the Republican plans irresponsible because they could either lead to big budget deficits or could “end Medicare as we know it.” Obama wants higher taxes on the wealthy, which Republicans call a job killer.

Romney hasn’t provided enough details to show how his proposal would balance the budget and deeply cut taxes. But his pick of Ryan signals a new policy-oriented shift that blunts criticisms that he won’t provide in-the-weeds details. Ryan, the U.S. House budget writer, is immersed in specifics.

The tax-and-budget issues are part of a wonky policy debate that has no easy answers, relies on projections and guesses and seems laden with political calculations no matter how objective the issue might appear.

But even Republicans might not be on board with wholesale Medicare changes, according to an AARP poll last year of Florida Republican voters. It showed that modest changes to benefits for future retirees are opposed by 66 percent of voters. Only 27 percent favor future reductions, which could include raising the retirement age, though the poll didn’t specifically address that issue.

Asked if they favored or opposed reducing Medicare benefits to help reduce the deficit, only 22 percent liked the idea. About 70 percent didn’t.