Look at a poll-any poll. Every one reflects that the "moderate center" is for securing the borders and against any form of amnesty. The republican politicians are ignoring the vast majority of voters at their own risk.
My brother-in-law, whose parents immigrated from Mexico (legally) before he was born, is strongly against illegal immigration. He's not happy with the Republican Party's failure to stop the illegals, though as a conservative Christian in law enforcement, he's not ready to threaten to vote Democratic.