The votes on the gun bill amendments were held under a unanimous consent agreement requiring 60 yes votes for an amendment to be adopted. That seems to have confused some of the coverage, in particular about whether this was filibuster-related or not. The answer, as I said yesterday, is that it absolutely is filibuster-related: Manchin-Toomey and the other amendments which reached 51 votes but not 60 were in fact defeated by filibuster, and that's what reporters should be saying. See yesterday's post for the general discussion of the gun bill and filibusters, but here I want to sketch out what we know about this particular Senate procedure.
Key points if you don't want to read a long post:
1. The 60 vote threshold procedure is relatively new.
2. It is a way of processing filibusters.
3. It is very similar to the demise of "talking" filibusters: it's efficient for the majority party, given a known filibuster.
4. Since the current situation is "filibuster on everything," there's always a known filibuster, so it's not surprising that 60 vote threshold votes have become common.
First, by way of introduction: virtually all bills in the Senate are considered under some UC agreement, which govern which amendments will be brought up and under what conditions. Without a UC agreement, a single Senator could block progress at any point, so they don't move ahead until they read a deal. That's as opposed to the House, where bills are considered under a "rule" drafted by the party-dominated Rules Committee and approved of by a simple majority vote of the whole House that the majority party always wins. UC agreements are limited only by the creativity of the drafters and what they can get everyone to go along with.
According to CRS, UC agreements incorporating a 60 vote threshold began "from at least the early 1990s." There were none during the Congresses that met from 1999 through 2004. Then there were eight amendments and three measure which used that standard in the 109th Congress, 2005-2006, and it became more common in the 110th Congress, 2007-2008. That's what a 2008 CRS report has; a 2009 version doesn't have any more, and if there are more recent versions they don't seem to be available. (I've also checked with Greg Koger, and he doesn't have anything more specific).
So: why a 60 vote threshold?
It makes sense in the context of knowing that the minority intends to filibuster an amendment (or a bill). For the majority, it accomplishes quite a bit. It removes the time that a cloture petition would need to sit before a cloture vote could be taken; it also removes post-cloture time. That means that getting a vote on a controversial amendment can take a short time, instead of basically chewing up an entire week. Not only that, but if a minority party wants and without a UC 60 vote threshold, they can filibuster each of a series of amendments, each one using almost a week of Senate floor time, even if they don't care at all about that particular amendment.
There's also the advantage, which either the majority or the minority might want, that it allows a substantive vote on something instead of a procedural vote. That might appeal to a minority which is being taunted to "allow a vote" on a measure; adopting the 60 threshold UC accomplishes that, at least to the extent that it confuses things.
It's not included in the CRS report (which precedes the true 60 vote Senate initiated in January 2009), but in a situation in which absolutely everything the majority proposes, it seems to me that there's another important reason for the majority to use a 60 vote UC instead of just going through a series of filibusters. If both sides have amendments, then the majority is put (as far as I can see) at a disadvantage. For majority-backed amendments, 60 votes are needed to overcome a minority-party led filibuster. But what about for minority-backed amendments to a bill that the minority opposes? Of course, if the majority party has the votes, it can simply defeat those amendments by simple majority vote. But if the minority party can come up with more appealing amendments -- ones that can command a chamber majority but that most of the majority party opposes -- then what? If the majority filibusters those amendments, then the minority only has to allow the filibuster to continue in order to bring consideration of the bill to a halt. Got that? Democrats are in the majority. The Republican Smith Amendment comes to the floor, an amendment that could get 51 votes by holding all Republicans and a handful of Democrats. If Democrats filibuster the amendment, and if Republicans just let them filibuster indefinitely...then Democrats can't move ahead to final passage of the bill, since the Senate is still stuck on the Smith Amendment. In other words, under filibuster-everything conditions and without the 60 vote threshold UC agreement, majority party amendments will need 60 votes, while minority party amendments will only need 50 votes. That's a pretty good reason for the majority to prefer the 60 vote threshold on all amendments UC agreement.
(Of course, by definition it's easier for the majority to get to any particular standard, whether it's simple majority or 60 or whatever. But it's not necessarily easier for the majority party to get to 60 than for the minority party to get to a simple majority).
So overall, the 60 vote threshold should be seen as yet another accommodation that the majority party makes to constant filibusters from the minority party. Just as with the decision to avoid the "talking" filibuster, it's in the majority party's interest to do things this way if you assume that the minority will always take advantage of the filibuster whenever it can.
Why, then, does the minority accept it? Well, partially it might be for the spin: as with the demise of the talking filibuster, it makes the filibuster less visible, and therefore perhaps more difficult to criticize. A lot of people believe that. I don't, really, but then again what really matters is whether the minority party believes it.
My guess, however, is that it's really for the same reason that the minority party allows the majority to dispense with the reading of bills or any of the other things that require unanimous consent that the minority habitually agrees with, and the same reason why the minority doesn't simply act as a cartel to block absolutely everything the majority proposes: the minority party has an excellent deal in the Senate, and they probably don't want to push too hard lest the majority impose reform that would change that. It's one thing to insist on 60 votes for every amendment; that's new in Senate history, but it has some basis in Senate rules and norms. To insist on the majority needing 60 on amendments and the minority only needing 51...well, that risks majority-imposed reform.
Okay, one more point. Remember all those charts you've seen that measured the rise of filibusters by counting cloture votes?
These 60 vote threshold votes are one of the reasons that those charts are terrible measures of how many filibusters there are in the Clinton, Bush, and Obama-era Senates. None of the nine amendment votes on the gun bill that the Senate has considered this week have produced cloture votes, but all of the Democratic amendments -- and, in effect, in retaliation all of the Republican amendments -- were filibustered. So that's nine more filibusters not accounted for in the cloture vote count -- cloture votes (not filibusters, but cloture votes) which were avoided by a procedure that didn't even exist in the 1980s and earlier, and which wasn't used regularly until George W. Bush's second term.
(Further complicating things: in a situation where most, but not all, things are filibustered, then you can get false positives here, too. That is: perhaps only one or two of the nine amendments would have really drawn filibusters. However, under conditions in which many or most things are filibustered, both sides may just agree to the 60 vote threshold because it's convenient. Yet anyone counting this is either going to come up with zero filibusters, thus missing real ones, or nine, thus (per this hypothetical) overcounting.)
Thanks to Greg K. and to another email correspondent, for pointers on this. I'll update/correct if there's anything more that turns up.