Reps Cutting Up the Safety Net?

I read the following from Kevin Drum (now back from vacation) at CalPundit:

I know conservatives hate to face up to this, and libertarians hate it even more, but the social safety net is really, really popular. You screw with it at your peril, and sometime soon it's going to become clear that Republicans have no support for a policy that's designed to cut back on them. The only question is, is "sometime soon" 2024 or 2024?

And then I read the following from Reuters

The U.S. Senate on Monday begins debate on a wide-reaching $400 billion 10-year proposal to give senior citizens and some disabled people long-awaited assistance in coping with the high cost of prescription drugs.

Unlike an earlier proposal by President Bush, the bipartisan Senate plan does not require Medicare beneficiaries to leave the traditional government-run health program and enter a private managed care plan in order to get the new drug benefit. People can keep the Medicare they have now, and still be able to get the drug assistance.

It does, however, give people in Medicare more choices, beyond rigid Health Maintenance Organizations if they want to go into private managed care plans. There is disagreement even among government economists on how many seniors will opt for private plans and how much money it could save the government.

Senate leaders have blocked out two weeks for what is expected to be a complex Medicare debate, as liberals and conservatives both try to remold the measure. But the bill passed with a broad bipartisan 16-5 vote out of the Senate Finance Committee last week, and is likely to pass the Senate with a healthy margin as well.

And I have to ask (as does James), exactly what part of the social safety net are the Republicans allegedly trying to tear up?