Reid's threat to McConnell is that, without agreement, he will go forward with the constitutional option, that is a simple majority vote. Reid says he has the 51 votes necessary. Ezra Klein has some intelligence on what the packages look like, and why the best outcome would be McConnell's refuses the deal.
In that case, Reid is preparing a backup plan that includes both of the items in the Reid-McConnell talks and one more: An innovative reform that changes who bears the burden for cloture votes.The choice for reform that actually will work seems pretty damned clear: the constitutional option including shifting the burden for cloture to the minority. The talking filibuster is off the table now, Reid has rejected it. So he needs to move forward with another plan that will work, and shifting the burden will do that. Significantly, this is a reform that Carl Levin, one of the key Democratic impediments to reform, says he could support: "I like that. [...] I'd love to be able to do that."
Right now, the majority needs to supply the 60 votes to break a filibuster. The minority only needs one vote on the floor. Under Reid’s backup plan, the burden would be reversed: The minority would have to supply the 41 votes required to keep a filibuster going, while the majority wouldn’t have to do much of anything. That means that if the minority only had 38 votes present in the room, the filibuster would end. It also means the minority could be forced to muster all their people to vote at times of the majority leader’s choosing: say, 3 a.m. on a Saturday. It would make filibustering a much more unpleasant experience.
Reid needs to give up on the wild goose chase of "bipartisan" reform, and just move forward with making the Senate work. This proposal to shift the burden of the filibuster can do that.
You can also call Reid's office at 202-224-3542, and encourage him to give up on McConnell and use the constitutional option to flip the burden of the filibuster.
9:42 AM PT: Sen. Dick Durbin told reporters today that the votes aren't there for a talking filibuster: "I would say the talking filibuster at this point does not have 51 votes." That makes moving forward on forcing 41 votes to sustain a filibuster even more important.