Thing is... The GOP did this to themselves in many ways.
Through their media arm and their rhetoric, there's this, kind of mythos they push, which I essentially boil down to this:
At some point in American History, everything was great, everything was grand, they had the whole wide world in the palm of their hands, and at some point, the liberals, minorities, gays and immigrants (depending on that particular persons view) ****ed it all up for everyone and took the country away from them.
Not everyone in the GOP believed it, not everyone in the GOP endorses that viewpoint, but it did originate there it would appear.