If Congress legislates to avoid the “fiscal cliff,” it will do so through a coalition of Republicans and Democrats. Cliff-avoiding legislation could, in theory, still spring from a deal between President Obama and Speaker Boehner. Or it could spring from the Senate.
But in either scenario, the Democrats must want to avoid going over the “cliff,” even though the plunge would probably work to their political advantage. And Speaker Boehner must be willing to put his Speakership at serious risk.
In addition, a bill must be formulated, and soon, that can command the support of enough House Democrats and Republicans to pass. The number of votes needed from one Party depends on the number of votes that can be obtained from the other, and I doubt that anyone has a clear idea of the number of votes a given deal could garner from either.
In short, the will may not exist to legislate a “fix.” And even if it does, there may not be enough time to pull it off.
Thus, the most likely cliff-avoiding scenario might be a punt that buys more time.