The simple answer is that political systems aren't as varied as you might think. There's egalitarianism, which is either unsubsidized (libertarian) or subsidized (socialism). Then there's those who think that some order should come before the individual, and those are either royalist, paleoconservative, "social conservative" or some form of meso-conservative (incl. neoconservatives).
But, as you might guess, there's a catch. Any political system picks up inertia like a ball rolling downhill. Thus whatever direction you go in, you keep going in... and so unsubsidized egalitarianism usually becomes subsidized (as in the 1960s in USA and Europe) and moderate conservatism eventually gets more conservative as it did under Reagan. The reason for this is that, believe it or not, political systems aim at visions of society. The more power they get, the closer they get toward realizing that vision, which is actually what the people who believe in them want.
Conservatives and liberals, by the way, have radically different visions for what they want out of society:
But, as you might guess, there's a catch. Any political system picks up inertia like a ball rolling downhill. Thus whatever direction you go in, you keep going in... and so unsubsidized egalitarianism usually becomes subsidized (as in the 1960s in USA and Europe) and moderate conservatism eventually gets more conservative as it did under Reagan. The reason for this is that, believe it or not, political systems aim at visions of society. The more power they get, the closer they get toward realizing that vision, which is actually what the people who believe in them want.
Conservatives and liberals, by the way, have radically different visions for what they want out of society:
http://www.volokh.com/2014/01/17/jonathan-haidt-psychology-p...
http://chronicle.com/article/Jonathan-Haidt-Decodes-the/1304...