The Senate wouldn't (not couldn't) do it because over 60% of the GOP Senate (and 100% of the Democrats) are part of the Establishment Cartel that got elected by giving away money we don't have to get people to elected them, and financing it with more debt.  They're afraid that if they get fiscally responsible, those voters will vote them out.  They're more concerned about keeping their jobs than they are about keeping this country from going over the fiscal cliff.  The only responsible people in Congress are the Tea party conservatives, about 36 of them in the House, and 20 in the Senate.  It's not enough to pass good legislation, but it's enough to block bad legislation.