The fall of communism was the worst thing for the Republican Party. Before, all factions could easily be united against the common threat.
The social conservative could argue for the traditional Christian values under threat from the godless Communists and their useful idiots. The businessman and his allies could rail against government planning and perceived allies of the Spviets in the labor movement. The national conservative and his allies in the intelligence services and military could get his military funding, his increased powers for the central government against asocial (communist-sympathising) and above all, America, as a strong bulwark in the world.
With no threat of communism, the contradictions began to unravel. Why would a staunch Christian care about some godless banksters profit margin? Why would a tradionally minded nativist American who wants strong borders want to open trade with Mexico? Why can a budget hawk justify the military budget considering the gutting of every other social program. There is no common powerful enemy that can really capture so many fears as the USSR was.
There's a lot of truth to this.
