I don't plan on voting a third party. However, if limited government and secure borders have finally become "fringe," then this country is screwed already -- regardless of who wins in November.
Limited government certainly isn't centrist anymore, not in the sense that we mean the phrase. I don't believe secure borders are a centrist demand, either, not when you get down to the nuts and bolts. You can poll folks all you want and they'll say they support secure borders... just have one 60 Minutes episode show a self-sufficient family of four that has been here for 6 or 7 years and is now being deported, complete with crying children. I believe most Americans would support their staying here and being given documentation.
So yes, some solid conservative values are closer to the fringe than the center and if we want to change the nature of the two parties, we have to move the center toward our desired direction. It is how the liberals have been doing it for decades, obviously with great success.