The exclusion of Ron Paul delegates by Rom-bots at the Republican Convention explains a lot.
Libertarian ideas, if clearly enunciated, are winning ideas. The trouble is that the Republican establishment is just as wedded to central government power as the Democrats; they just want a different emphasis on where and how the power gets used.
A recent Zogby poll was most enlightening on this subject. Only about ten percent of the population self-identifies as libertarian. But, if the question is phrased, "are you socially liberal, and economically conservative, in other words, libertarian?" the number jumps to 44 percent. If the question is phrased, "are you fiscally conservative and socially liberal?" it jumps to 59 percent.