The Romney-Ryan plan, by contrast, achieves its savings by turning Medicare into a voucher whose value doesn't keep up with expected increases in healthcare costs -- thereby shifting the burden onto Medicare beneficiaries, who will have to pay an average of $6,500 a year more for their Medicare insurance, according an analysis of the Republican plan by the non-partisan Congressional Budget Office.

Moreover, the Affordable Care Act uses its Medicare savings to help children and lower-income Americans afford health care, and to help seniors pay for prescription drugs by filling the so-called "donut hole" in Medicare Part D coverage.

The Romney-Ryan plan uses the savings to finance even bigger tax cuts for the very wealthy.