With the Democrats’ Senate Majority now dramatically reduced and the seats up for grabs in 2012 looking good for the Republicans, now is a propitious time to revisit the question of reforming the filibuster since it’s much less clear whose minority oxe would be gored. In a sense perhaps it makes no sense for the Dems to entertain reform, given how the Republicans dealt with things in 2006-2010 and given the fact that it’s now much more likely for them to get gored. But for the sake of civics if nothing else, let’s entertain the question. Because I think it’s much less of an all or nothing exercise than most imagine.

Here’s the thing that people tend not to realize about the modern filibuster: it places all the onus on the majority and almost literally none on the minority, thus creating a massive incentive for endless filibusters. Let me explain.

How many Senators do you need to get on the floor to break a filibuster? 60.

How many do you need on the floor to sustain one? 1.

This is what people tend not to realize when they ask why the Majority Leader isn’t ordering them to get out the cots and make people stay up all night. It’s just too easy to sustain a filibuster for that to make any sense.In the outgoing Congress it would have meant getting all 60 Senators to stay on the floor indefinitely while the GOP only had to make sure one senator was on the floor at any one time to raise an objection to ending debate. Maybe two at any one time if you figure the need for occasional bathroom breaks. And since each party is going to have somewhere on the order of at least 40 senators, taking shifts indefinitely just isn’t a problem. And even though people think you’ve got to sit there reading the phone book or talking forever or whatever else, you don’t. You don’t have to do anything except sit there and be ready to stand up for 30 seconds and make an objection. So while the majority needs 60 Senators cooling their heels on the floor, the minority can just have one or two sitting there playing Angry Birds on their iPhones.

Here’s another part of the equation. Everyone knows you need 60 votes to break a filibuster. But it’s not 3/5 of the votes, it’s an absolute 60. That’s why you’ll note that when a filibuster is a broken it’s usually by a vote of 60 to 30-something. In other words, the folks in the minority, the folks filibustering, don’t even need to show up. I’d like to say they can just dial it in. But actually they don’t even need to do that.

These are, to put it mildly, very perverse incentives.

Given what’s happened over the last four years, it’s probably a bit rich to expect Dems to make a good faith effort to reform or limit the use of the filibuster. Indeed, it’s probably unrealistic to expect the minority ever to do so. And frankly I don’t even think abolishing it outright is even a good idea. It probably makes sense to have some brakes on simple majority votes on the Senate. But some brakes, not absolute brakes, which is what the Republicans have brought it to now. (And yes, look at the evolution over the last 20 years: it’s the Republicans.)

But as you can see, I think it would be fairly easy to preserve the filibuster while also shifting the incentives around in such a way that you’d be more sure the minority felt it was a critically important issue. And maybe something they’d have a hard time sustaining on a permanent basis. If you had to keep 40+ Senators or even some substantial number of Senators on the floor more or less indefinitely to keep the Senate bottled up and preventing a vote, believe me, it would happen far far less than you’re seeing it now. And I’m pretty sure you’d see de facto 60 vote rule become a thing of the past.