The GOP’s share of the Hispanic vote dropped in 1988, 1992, and 1996, before rising under Bush. Second of all, you would expect the Republicans to do better and better among Hispanics as the last amnesty receded into the past, and its beneficiaries assimilated and started to move up in the world. ~Ross Douthat

Someone would expect this, I think, if he thought that assimilated, successful immigrants normally have a natural tendency to break with the Democratic voting habits of most new immigrants.  This seems reasonable, but if it were true the GOP would be awash in Greek, Armenian and Asian voters.  Generally speaking, it is not.  Voting for Democrats in many ethnic immigrant communities is just the obvious thing to do, especially for those who come from political traditions that stress some greater measure of social solidarity.  Interestingly, these immigrants often tend to concentrate in large urban areas that either lean or are solidly Democratic, so this traditional preference for Democrats is reinforced by the very process of assimilation.  Further, suburbs are no longer always a reliable Republican stronghold, so it may be that even assimilated, successful immigrants who come out to the suburbs may not so much adopt suburban Republicanism as they will help speed the transformation of many suburbs into Democratic turf.  Inherited cultural and political attitudes are often more determinative of voting patterns than class or income.  The GOP has to be hoping that historical materialism is at least partly true and it has to be hoping that ideas do not, in fact, have many consequences at all (or at least fewer consequences than a nice salary).