Kentucky counties that have received the most immigrants (whether measured in absolute number or in percentages) tend to have stronger growth in wages and lower unemployment than counties without significant immigration. This does not prove that wages are immune from an influx of immigrant workers, but it does emonstrate that those counties in Kentucky with a significant immigrant influx are also the counties that prospered more over the same period.
I've been paying close attention to online political discussions, and this is currently one of the big ones. Other than terrorism and the war, this is the most-discussed topic on political blogs that skew right. Literally thousands of conservative political blogs are firmly anti-"amnesty" and they're talking about "illegals" and linking to news articles that reference Mexico. A few noteworthy exceptions on the right are "pro-reform," but they aren't talking about the latino community in a positive context either - you see a lot of "they take the jobs no one else wants to do."
Very few people on the left have discussed immigration at all, other than making the sweeping generalization that "the republican party has lost the latino vote for decades over this," as if any group of people that large cares about only a single issue.
Cruz' pro-business perspective should be included in the blogosphere's discussion.