This is interesting; Greg Mankiw, a high-profile economist who also serves as a co-chair for Mitt Romney's Economic Advisory Council, was a signer of this op-ed in today's Dallas Morning news. Here's an excerpt:
This is the most far-reaching and thoughtful reform of our immigration system in four decades and one that will significantly enhance American competitiveness. As with any political compromise, improvements can be made. But the basic framework is one that conservatives should support. Indeed, for conservatives who opposed last year’s immigration bill, this package represents a step forward.