The only way cuts to Medicare and Social Security benefits can become law as part of a debt ceiling deal is if a significant number of Congressional Democrats vote for those cuts. A bloc of Congressional Democrats can stop these cuts if they simply vote against them, using the leverage they have.
Republicans control the House of Representatives and in theory could pass a deal on a party line vote, but in reality that won’t happen. A significant number of House Republicans, for a variety of political and policy reasons, are not going to vote for any deal that does emerge. To pass any deal, Speaker John Boehner is going to need several Democratic votes. If all House Democrats vote no, a deal would not pass. And if the majority of House Democrats who claim to oppose cuts to the social safety net are serious, they have huge leverage to prevent defections in their ranks. House Democrats could threaten a vote to strip any defector of his/her leadership or prized committee positions.
The Senate, on the other hand, is still controlled by Democrats. No deal can become law without getting votes for some Senate Democrats. Even a modest size group of Senate Democrats, in theory, have huge leverage to stop any deal. A filibuster by any 41 Senate Democrats, likely less would be needed if a few diehard Republicans join them, would be enough to stop any austerity package. More importantly, the deal can’t pass unless Senate Majority Leader Harry Reid brings it to the floor for a vote. If just 27 Senate Democrats promise to remove Reid from his leadership position if he brings Social Security cuts up for a vote, that promise alone should be enough to stop a deal cold.
If they have the will to use every tool at their disposal, even a modest coalition of Congressional Democrats could stop passage of any bill containing Medicare or Social Security benefits cuts.
Congressional Democrats simply must say no to any deal containing cuts to the social safety net. This would force Obama to use the 14th amendment to declare the debt ceiling unconstitutional. While the administration claims they don’t think the Constitution grants them this power, does anyone really think if that were the only option open to him, he would instead choose default? A move that would cause massive unnecessary damage to Wall Street? Obama choosing to hurt his Wall Street donors for no reason? Not going to happen.