BY TRISH TURNER --

Sen. John McCain, R-AZ, did not look like a man who had just lost a vote in the Senate, as his amendment to healthcare legislation that would have required a restoration of the nearly $500 billion in cuts to Medicare programs failed on a vote of 42-58, and afterward, he offered a hint at why. When asked what the next Republican amendment would be, McCain smiled ruefully, "Medicare."

Republicans clearly feel they have a firm political footing on this issue with seniors, despite the endorsement of a Democratic alternative amendment by the nation's largest seniors organization in the country, AARP, which sent a letter to Senate Majority Leader Harry Reid, D-NV, supporting the cuts and opposing McCain's amendment. And Democrats confirmed the explosive political potential of making any cuts to the seniors' program that is considered virtually untouchable, arguing passionately for weeks on the Senate floor that no cuts will be made to benefits.

An amendment by Sen. Mike Bennet, D-CO, up for re-election in 2010, quickly materialized as an alternative to McCain's, that expressly guarantees no cuts will be made to Medicare beneficiaries' benefits. The amendment was accepted unanimously.

"Guaranteed benefits, there is not a single guaranteed benefit that will be cut under this bill. I defy anyone to find one!" Sen. Chris Dodd, D-CT, shouted on the Senate floor, as he, himself, faces a very stiff re-election effort back home.

McCain merely mocked the endorsement by "that liberal Democratic group," referring to AARP, and noted the group has in the past opposed cuts to Medicare, though McCain, himself, has also proposed cuts in the past.

Next up for Republicans, an amendment that would strike the $110 billion in cuts to Medicare Advantage, a private, government-subsidised supplemental healthcare program for seniors.

Sen John Thune, R-SD, told Fox, "It's safe to say we believe the debate about Medicare cuts has not been fully debated yet."

Medicare Advantage cuts (not "guaranteed benefits"), hospice care, home healthcare, skilled nursing, these are all among areas of focus for GOP amendments related to Medicare, according to a senior Senate GOP leadership aide.

Meanwhile, Democrats have had to pull back on their next amendment, one offered by conservative Sen. Ben Nelson, D-NE, which is intended to tighten the restrictions in the Reid healthcare bill that ban federal funding from being used for abortions. Nelson said some pro-life groups in his home state had concerns about bill language originally circulated, so changes are being made "to directly or nearly directly follow the Stupak language."

Nelson was referring to a House-passed measure that bans all abortion coverage from the public healthcare exchanges, or marketplaces, where those with federal taxpayer-funded subsidies could go to purchase healthcare coverage. A separate rider plan would have to be purchased from private insurance companies.

Pro-choice Sen. Barbara Boxer, D-CA, said Thursday she is certain that Nelson's effort will be defeated, calling it "the biggest rollback in three decades for women's healthcare."

Nelson conceded that outside pro-life groups will now be given the time to lobby members to support the legislation, and Sen. Orrin Hatch, R-UT, who was to be a co-sponsor of Nelson's amendment, said that's exactly what he wants, accusing Reid of rushing Nelson's amendment to the floor. Nelson disagreed with that accusation, but noted that now, with the changes to the amendment being made, "Senator Hatch's concern is moot."

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