First Rand Paul is a constitutional conservative that leans libertarian, so am I. I agree with libertarians on lots of issues that pertain to personal liberty. They lose me on abortion (Paul is very pro life), same sex marriage (Paul opposes same sex marriage), open borders (Paul wants to secure the border) and free trade (no such thing exists).
I take some heat from social conservatives over the War on Drugs (we lost) and heat from neocons over the war on terror with looks more to me like a war on the Bill of Rights.
My point being that if someone agrees with you most of the time that person deserves your support most of the time. It is down right stupid to undermine an ally that agrees with you 70-80 percent of the time. Take them to task OVER THE ISSUES the other 20 30 percent.