The *real* Libertarian, the former New Mexico governor not Ron Paul, has gotten the Libertarian Party presidential nod.
First, per a link inside this Daily Beast overview of what he could do in the race, I love how the WSJ disses his "outside the mainstream" views on gay marriage and legal marijuana, when they're both majoritarian (were I not voting Green, he'd likely be ahead of Dear Leader as my second choice).
Second, it's true that he walks the libertarian walk in a way Ron Paul doesn't. Above all, having been an executive, he had no problem pulling the veto trigger. Paul, of course, has brought bacon a-plenty home to his Congressional district, then offered the same excuse as Ayn Rand did with Social Security.
How "pure" is he? He vetoed a bill passed by the N.M. legislature that, in its initial form, had been pushed by his own wife. Still vetoed it; said it had been changed too much.
Third, he is a social libertarian to a degree far beyond Paul. He doesn't "favor" gay marriage because he doesn't favor the state regulating marriage at all.
That said, he's no Jill Stein. He still stand well behind her in my affections. He's got "issues" as well as issues.
He was strongly pro-voucher for public schools, built multiple private prisons (including one in Hobbs when I lived there), is big on privatization in general, and, while not anti-environmental, isn't strong on it; Wiki lists his full political positions (which, unlike most politicians, don't change).