for starters this may have some leads as to what you might want to look into http://www.addictinginfo.org/2012/01/04/10-reasons-not-to-vote-for-paul/ personaly his stances on church state relations is a big sticking point for me, but as conservatism in this country has been hijacked by religious concepts instead of just classical liberalism. leading to legislation of morality. His claim of libertarian is a bit bs from what ive gathered, as he is too obsessed with pushing his crap than what a "true libertarian" would be in the classical sense (no true Scotsman blablabla) But a HUGE pissoff to me is his desire to cut off federal emergency response funds for natural disasters. being from MO and having the Joplin tornadoes in recent memory, his reasoning is BS. his claim that the federal funds encourage people to build in risky places to reap fed funds when their house gets destroyed.

I find that most people support him for 1)legalizing pot 2)wanting to ban the fed (which i just finished a legal history paper about) 3) getting out of the current conflicts (we havent declared war since WWII due to the war powers act)
those things are well and all, but for those 3 things, i'm not willing to deal with the rest of his insanity. plus how much could he live up to v a congress of his foes. he would have to rely heavily on executive orders and his stance on the constitution would prevent that because that would be overstepping the constitutional powers the founders set so his strict constructionist roots would make himself be almost useless