Here's a Gallup table which shows that Congressional voting preferences among Hispanics (and blacks and whites) have not changed since the Arizona illegal immigration law was passed. And notice the famous 2-to-1 Hispanic preference for Democrats.
Republican leaders are willing to let Hispanic immigration destroy the long-term prospects of the party, and for what? So their fellow elites won't think they're bigots. They'll be unemployed, but at least they won't get called names.