Allahpundit did some detective work on how the immigration bill cloture vote shook out today. He notes that when the voting machine was turned on there were 19 ayes and 21 nays cast immediately. He also notes that only five switches from Tuesday’s vote, from yay to nay, would doom the measure and there were six switches in the 21 nay votes, indicating that the cloture vote would fail:

They’re supposed to vote in alphabetical order, but if they’re not present when the roll is called — or if they are present but would rather keep mum to see how things are shaking out — they get skipped, and can then approach the podium afterwards, when they see fit, to cast their vote. …

Forty members voted during the alphabetical roll. Note that fully six of them switched — and only five switches total were needed today to kill the bill. The other fencesitters must have noticed, sensed the momentum, and recalibrated their own votes accordingly. The other notable is the Burr-Harkin-Pryor-Nelson run. They all voted no, all in succession, and were all switchers, which makes we wonder if they had an informal agreement among themselves.

Sen. Richard Burr, R-NC, cast the 35th nay vote at a time when it was almost assured that the nays would reach 40.

Sen. Sam Brownback was not as cunning as Burr. Allah has the video proof (scroll down) that Brownback changed his vote when he saw the measure would fail:

He voted yes right at the very beginning, during the alphabetical vote, probably thinking that cloture was going to pass. Then, when it died, he switched to a no.