I think they've known this for a while. That's why you have seen an increase in the reporting of crack downs on illegals, the companies that hire them, and the guard on the border. (Even though most of the illegals that have been nabbed have been released.)
Nothing to get excited about. It's just the politicians doing what they always do. That is, doing what the people want just far enough ahead of an election to have an impact.
The Republican base has been upset with their representatives (and I use this term loosely) for quite some time. It's good to see it showing in some poll results. Maybe it will shake things up a bit.