It's going to take several Dims in opposition to amnesty to defeat it. McCain, Graham and Kyl will all support amnesty (unless Kyl flip flops again and opposes it). Several Dims opposed it in 2006 and 2007, but there are even more of them now.
Some people say this has no chance because it's an election year. I hope they're right, but am not so sure.
So will Brownback. I was a Senate watcher when S.2611 was active, and besides being a bill cosponsor, his voting pattern indicated being in the McCain/Graham camp. Cornyn too, but he's more slippery.
My ultimate take is that the issue of Congress finding a way to get the heat and taint off illegal immigrants isn't a matter of "if," rather, it's a matter of "when."