I wonder if any Republicans have read this (my emphasis):
Don’t castrate the party, smooth out the many sharp edges of the GOP’s platform and message. Keep supporting tax cuts and less regulation, but add an agenda and message aimed at the middle and working class. Remain pro-life, but don’t appear opposed to Planned Parenthood or contraceptives, and return to supporting exceptions in instances of rape or the health of the mother, as President Bush did. Stay committed to religion, but don’t reflexively doubt the science of evolution and global warming, or the promise of stem cell research or renewable energy. Oppose gun control, but why force yourself to oppose background checks? On all of these issues, the GOP need not compromise on its core policy objectives, but can’t afford to consistently stake out ground so far from the center. That allows Democrats to cast the party and their core beliefs outside of the mainstream, which has already happened on abortion.
Finally, and again, I think Cohn is spot-on here:
That makes it even more important that immigration reform passes. Sometimes, allowing issues to disappear can be just as helpful as rebranding.
Why would Republicans kill the immigration bill? Just get the darn thing off the table. Why hand the Democrats a club with which to beat you in 2014 and 2016 (and beyond)?