Romney lost because he did not appeal to the millions of Americans who have seen their standard of living decline over the past decades. They're nervous about the future. When Romney did not address their concerns, they either voted for Obama or didn't vote at all. If the next Republican candidate can address their concerns effectively, he will win. And, amazingly enough, he'll win a lot more Hispanic votes in the process. A lot from other groups, too.
It would do more than any immigration bill or outreach program ever could.