There are a number of issues I come back to over and over again. One of them is that Americans do not care as much about immigration as politicians and the media claim (also discussed in my forthcoming at any second book, Irresistible Forces). Right now the DREAM Act is being debated, and through CNN we have this nugget from a Gallup poll:
Similarly, the country is less concerned with Congress acting on the DREAM Act, which would provide a pathway to citizenship for undocumented immigrants living in the U.S. who were brought to the country as children. Thirty-eight percent say it is not too/not at all important.
Immigration restrictionism is not as popular as it appears, or at least it does not rile people up quite as much as portrayed. That increases--albeit minimally--the chances of passage.