However, the evidence, and specifically the evidence concerning Latino voters, doesn’t support that theory. In fact, what the data show is that for Latinos and most other Americans, party identification and voting behavior are based on policy preferences much more than on group identity.
This can be seen in data from the 2012 American National Election Survey (ANES), and the data from earlier ANES surveys show basically the same thing. For Latinos, and for almost all other major voter groups with a clear partisan leaning — Jews, gays, union members, white evangelicals, etc. — with the exception of African-Americans, party identification and candidate preference are strongly correlated with policy preferences. Conservative Latinos overwhelmingly identify with and vote Republican. So do conservative Jews, gays and union members. On the other hand, liberal white evangelicals overwhelmingly identify with and vote Democratic.
Moreover, for Hispanics, the policies that really matter are those involving the role of government and social programs, not immigration (or cultural issues). So even if some Republicans support comprehensive immigration reform (and it’s unlikely to be more than a minority of Republicans even if it is allowed to come to a vote in the House, just as it was only a minority in the Senate), it’s very unlikely that this would have much impact on Latino party identification or voting behavior. The real problem Republicans have with Latino voters is that the GOP’s positions on the role of government and social programs are far to the right of those of most Latino voters. And that’s not likely to change any time soon regardless of what happens on immigration reform.