Gary North has an interesting article on how political parties work. The elites control the higher levels of both parties. There are real differences between the two, but within bounds policed by the elites. The elites select the presidential nominees of both parties by providing the funding necessary for nationwide campaigns when few average folks are paying attention. The only way to beat them is for grassroots conservatives to unite around a candidate before the race begins, as happened in 1964 and 1980. Grassroots conservatives and libertarians need to stay involved in the GOP to gradually change the system over time.
How the Council on Foreign Relations Controls Conservative Republicans