The Republican political establishment sees immigration reform as a political necessity. Much of the party's base sees it as the end of the rule of law. And therein lies the problem for a party trying to pick itself up off the mat following an across-the-board defeat in 2012.
It's not clear how Republicans can bridge the growing divide between how the establishment views immigration (a political problem that needs to be solved yesterday) and how some significant portion of the base views it (a foundational principle about not rewarding rule-breakers).
I imagine the establishment will just plow forth with it. The potential consequences are catastrophic in the near- and intermediate-term.
Immigration reform will almost have to pass the House with a minority of Republicans and a majority of Democrats.