At his core, Friedman was fundamentally about a person's right to choose the direction of their own life. That's it -- really all you have to understand about the guy.
The GOP seems to love Friedman right now, even though they don't understand him and that makes him an easy target for the opposition. In truth his arguments were fundamentally no different from his oft-adored 'liberal' peers: Henry Simons, Ludwig von Mises, and Friedrich von Hayek. Economic freedom is essential to attain political freedom.