But there's more to this story about the filibuster. Even if opponents of the filibuster do not have the votes to kill it, they believe that they have much to gain by threatening to kill it. Sen. Tom Udall (D-NM) and Sen. Tom Harkin (D-IA) are among the leaders of a movement to destroy the filibuster with a so-called "constitutional option," a movement talked up by Ezra Klein. Here's the potential game plan for the exercise of this "option":
If Vice President Joe Biden -- who has spoken out against abuse of the filibuster and has been studying ways to reform it -- were to rule on the first day of the next session that the Senate has the authority to write its own rules, Republicans would immediately move to object. Democrats would then move to table the objection, setting up the key vote. If 50 Democrats voted to table the objection, the Senate would then move to a vote on a new set of rules, which would be approved by a simple majority.
The simple act of holding the vote would have a therapeutic effect on the Senate even if it fails, said Udall, as it would inspire fear that abuse of the rules could lead to their destruction.
The point here is not that opponents of the filibuster believe that they can succeed; they only need to appear to believe that they can succeed. This appearance of success could intimidate believers in the filibuster to try to cut a deal to save the procedure.
Of course, the use of this option could easily open Democrats up to this narrative: having taken a beating in the 2010 Senate races, Democrats now change the rules to make it easier for them to pass legislation. Assuming that the midterms do result in significant gains for the Republicans (not exactly a ludicrous assumption), the public momentum would seem to be against the Democrats. This kind of rule-changing could easily seem a desperate move to grab as much power as possible in the waning days of "progressive" ascendancy.
While many "progressives" would be glad to push through the most radical measures possible on a 51-vote margin (or maybe even a margin of 50-50 +tie-breaking vote by the VP), many Americans hold a contrary view that, if a measure can't achieve broad bipartisan support, maybe it really isn't that moderate and that maybe moderation is, after all, a good thing. And many of the bills the Democrats most blame the filibuster for blocking are quite unpopular. Many voters might not see the filibuster as frustrating but as defending popular sentiment.