As I said before - Bush won 44% of the Hispanic vote in 2004. Politically speaking, many Hispanics are conservative, especially socially. Its only immigration and the racist policies of people like that idiot sheriff in Arizona that's driving them away.
If someone like Jeb Bush or Rubio is the candidate, ie someone with a sane immigration policy, they could make significant inroads. They may not win the Hispanic vote outright but they don't need to. They just can't lose it 70-30 like they did this time around.