En español | Jubilant supporters chanted, "Medicare! Medicare!" after Democrat Kathy Hochul shocked the political world with her upset win in a special election in New York's conservative 26th Congressional District, for a seat held by Republicans for all but 16 of the past 154 years.

Sign up for AARP’s Health Newsletter.

Activists protest GOP efforts to cut Medicare. — Photo by: Alex Wong/Getty Images

The chant reflected the fact that Hochul had campaigned strongly against the Republicans' controversial plan to overhaul Medicare. Her come-from-behind triumph in May was thus widely seen not only as a rejection of that plan, even among many Republican voters, but also as an indicator that the new battle over Medicare will be a defining issue of the 2012 elections.

"We will keep the promise made to our seniors who have spent their lives paying into Medicare, so they can count on health care when they need it most," declared Hochul, 52, at her victory celebration.

Democratic strategists immediately began planning to campaign against the GOP Medicare plan in nearly 100 competitive House districts in 2012, even dreaming of sending House Budget Committee Chairman Paul Ryan, its author, back home to Janesville, Wis.

The Ryan plan

Ryan's plan — passed by the Republican-controlled House as part of its budget proposals but rejected in the Senate — aims to terminate government-run Medicare for everyone who becomes eligible for the program after 2021, replacing it with a voucher plan known as "premium support." That system would provide new beneficiaries with a government subsidy to buy their own private insurance on the open market.

Both parties already are jockeying to frame the issue in ways their strategists hope will appeal to voters in the 2012 elections. Democrats paint the Ryan plan as "ending Medicare as we know it" and switching more costs to older and disabled Americans. Republicans portray it as a necessary means to curb government spending and reduce the national debt. In the current deficit debate, the GOP message so far has presented a stark choice — either end Medicare as an entitlement program or drive the country into bankruptcy.

But beyond the political rhetoric, health policy experts say that while it's true that Medicare spending needs to be reined in, this can be achieved by less radical solutions. They also point to political ironies inherent in the Ryan plan. It relies on setting up health insurance exchanges in the states and providing extra subsidies for low-income beneficiaries — both of which are features of the Affordable Care Act, the new health care law the Republicans want to repeal.

Next: Ryan Plan details. >>