Here is the thing. We need to look at where those illegals will settle by 2016, are they blue or red districts? If they aren’t going to change the California vote in 2016, it buys us time. I am worried about red states where the vote will matter.
Worst case scenario, they turn Texas and Georgia from red to purple, and Florida from purple to blue.
FL will become the southern equivalent of PA, with huge Dem urban advantages outgunning the suburban/rural GOP advantage. No one at the state level will care, since the state legislature will remain GOP and the House districts will be gerrymandered to ensure incumbent re-election.
For the national election, it will mean that the GOP nominee will have to win all the marginal states (OH, VA, TX, AZ, NC, IN, WI, MI) in order to have a chance at election, since the left coast, the northeast, and FL will be in the Dem's pocket.