National Journal's Michael Catalini is dead-on here.
....there’s evidence that Hispanic resistance to the Republican party is as rooted in the GOP’s skeptical view of government, as it is their disagreement with GOP hardliners on immigration. The Republican Party calls for smaller government, but many Latinos look to government assistance as a necessity.
Forty-two percent of Hispanic voters say that a government job offers the best chance of gaining career success, compared to only one-third of white voters, according to a June Allstate/National Journal/Heartland Monitor poll.
I've written at-length (here and here) about the faulty notion that moving toward the middle on immigration will cause Hispanics to move toward the GOP. Practically, there's nothing to suggest that would happen, and theoretically, there's even less to support it.
Most Hispanics (roughly 70%) agree with Democrats on key economic issues and, more fundamentally, the role of government itself.
Why would they abandon the party they agree with 80% of the time to have an affair with the party they agree with 20% of the time?
When Bill Clinton signed welfare reform, it made conservatives look more fondly on him, but they weren't any likelier to vote for him. They stuck with the party that also believed in welfare reform and everything else (taxes, abortion etc), as well.
As I wrote earlier this week, it doesn't mean the GOP shouldn't do immigration reform, but it means they should pursue it for the right reasons and with realistic expectations. If they expect political gain and nothing, electorally, comes of it, the move could further divide the party.
UPDATE: Conservative writer, Ross Douthat, notes:
.... there is simply no plausible case that gratitude to Marco Rubio and Jeff Flake will convert a liberal-leaning voting bloc into a true swing constituency, let alone a Republican-tilting demographic.