By "Libertarian-Republicans", I assume you mean the same type of people (citizens) who would follow advise like - "Rage against the machine and Vote for Gingrich". People who probably thought RP was an "unelectable kook" and might have agreed with him on everything but his "foreign policy", because as you know "Iran is the biggest threat to world peace"! <-sarcastic
Sure, Rand has appealed to "mainstream", tea party types especially, but so have idiots like Palin, Bachmann, and the like. Hell, even Beck and Hannity are mingling with that label nowadays and I doubt its because of Rand.
Im not trying to bash Rand, but again, he hasnt blazed s**t.