[batter]

I looked at a post on HotAir.com. They may be right on this:

I’m guessing some of the bill’s supporters are nervous about bringing it up for a final vote before the killer Dorgan amendment has itself been killed, so they want to continue the debate for the time being. (Specter hinted as much earlier today.)

They have a link to Specter's 'hint'.

[unspun]

Sen. Sanders: "This legislation has little to do with (regulating immigration) and everything to do with wages corporate America wanting to drive down wages."

I'll agree with that liberal's sentiment in a minute!