From what I remember, a couple of fence sitters got lots of faxes and e-mails screaming for them to oppose this before it came up for a vote. It looks like your going to have to do it all over again.
You are spot on. In fact it really came down to one guy in Mount Prospect (I think) that switched his vote after being inundated with calls and faxes. The sad thing is, sooner or later the Illegal Alien lobby will get what they want. In this state, they have the votes to do it once the trash hits the assembly floor.