If the favorables stay above 40%, I think we stand a very good chance of getting a bill before next March. If they go much lower, the procedural hurdles are basically a sideshow. Democrats can tell themselves that if they don't pass a bill, they'll look like fools, and their demoralized base will stay home, and if the numbers are close enough, maybe that's true. But favorables in the 35% range will mean they've got everyone except their base against them. They really can't win an election on that, especially not in the Senate. I don't see them ramming through huge bill on a party line vote when significantly more than half the country hates it.
But who knows? Maybe Obama has another speech up his sleeve.