The reason the two parties have been around for so long is their ability to morph themselves into whatever they need to be in order to win. Sooner or later I think we'll see a more minority friendly GOP, as unlikely as that seems now.
I can see this happening only under two conditions. First, the GOP must lose at least three straight presidential elections in a row along with multiple midterms. Second, a significant number of working class whites must ditch the GOP over the course of those three electoral cycles in such a consistent fashion that the GOP realizes that expanding their share of the minority vote will be the only way they win going forward.