Continuing the conversation of immigration and Senate process (scroll down to see jousting GOP aides this weekend), a former leadership aide e-mails:

The innovation here isn’t a divisible amendment. The right to divide an amendment is available to any member (if the amendment qualifies for division). The innovation is the Majority Leader using his majority power to make it happen POST-CLOTURE, and, in so doing, block out other amendments from being offered. On immigration last year, Frist built a “clay pigeon” amendment, composed of proposals from conservatives led by Jon Kyl, then took it to Reid and told him to agree to a deal on votes for those amendments or he would pull the trigger on it post-cloture and make the Senate vote on each idea. Reid and the liberals backed off and cut a deal to guarantee the conservatives their votes. This year, Reid took a “clay pigeon” amendment, composed of proposals from those who could make up 60 votes in favor of cloture, and (absent any other arrangement) apparently plans to actually blow it apart so post-cloture so that votes are held. Those in on the process deal get their votes; those who aren’t, won’t, under this process. (And post-cloture requirements are all designed to bring the the upon which cloture was successfully invoked to a final vote, up or down, making it very difficult [but not necessarily impossible] for someone who isn’t a Majority Leader to call up other amendments or motions.) However…this torturous road currently leads to a flat dead end if the tax provisions remain in an S-numbered bill. Including such provisions violates the Constitution, making the bill dead in the House right now. Even if the tax provisions are dropped, or the House waives the Constitutional barrier, or the process for marrying up the two bills is altered in some way, those who want to pass this bill—and those who don’t want it to pass—have a massive variety of procedural challenges/options still to work through that affects the timeline and prospects for finishing the bill with a conference committee, the formal way the House and Senate negotiate bills. …. Between now and the recess, there will be a blizzard of cloture petitions Reid will need to file to try and wrap things up…