Obama's plan relies heavily on cutting payments to health care providers. Critics say that could cause some doctors to stop seeing Medicare patients.
The Romney-Ryan proposal would give future retirees a fixed amount of money to pick their health insurance from competing private plans or a government program. It would limit taxpayers' burden, but also force many patients to pay more of their health costs.
Romney is using the unpopularity of Obama's health care law to try to finesse a political problem.
Ryan has embraced Obama's call for about $716 billion in Medicare payment reductions, over 10 years, a move Romney opposes. In his whiteboard demonstration Thursday in South Carolina, Romney indicated his biggest objection to the $716 billion in reduced growth -- or savings -- is that the money is used to fund other elements of "Obamacare."
But those cuts are part of Ryan's overall budget blueprint. Ryan said he included them in his House plan because they were already part of current law — in essence, because Obama did it first.
Eager to confront what they claim are Romney's distortions, Obama campaign aides produced their own "video whiteboard" Friday. In it, spokeswoman Stephanie Cutter says Obama's $716 billion savings comes from reductions in "waste, fraud and abuse" in the Medicare program. She labels as "ridiculous" Romney's claim that his GOP plan would extend Medicare's life.
Independent groups say Romney hasn't provided the details needed to support his claim.
Some Democrats seemed happy to have another campaign week go by with comparatively modest focus on the nation's 8.3 percent unemployment rate. The economy has remained voters' top priority in the campaign so far, although several polls conducted before Ryan's selection suggested the federal budget deficit was not far behind.
A Pew Research Center poll in June, for example, found 35 percent called "jobs" the most important issue in deciding their vote, while 23 percent chose the budget deficit, 19 percent health care, 11 percent Social Security, 5 percent immigration and 4 percent gay marriage.
Friday's Wall Street Journal editorial page -- an important forum for conservative debates -- said, "The destructive policy and unpopularity of Obamacare have made Paul Ryan's reform politically possible."
The Obama camp is trying to make it a political liability.
Ben Feller reported from Washington. AP writers Steve Peoples in Glen Allen, Va., and Ken Thomas and Julie Pace and Deputy Director of Polling Jennifer Agiesta in Washington contributed to this report.
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