Ann Romney's comment that Hispanic voters need to get past biases shoved on them by Democrats is, I think, a good indication of why Republicans are finding it so difficult to gain traction.
It really is a message that would resonate well if they could just get past some of their biases that have been there from the Democratic machines that have made us look like we don't care about this community.
You catch more flies with honey, as it were, and this comment is the equivalent of bumbling around the room with a flyswatter. You don't gain votes by telling people they're easily brainwashed and cannot determine their own self-interest on their own.
Even worse, Romney and others are making these comments in the context of a convention that adopted an aggressively anti-immigrant platform. The biases to which she refers, then, are rooted in very public declarations by the Republican Party itself, and not by any magical brainwashing machine.