He is a devout libertarian, which is scary, because his ideals contradict with the beliefs of the majority in the country. He doesn't believe in providing government services such as healthcare, and has no inclination to support the US infrastructure other than to turn it into a free-for-all. Also, he wants to install a flat tax rate. This benefits no one but the rich. And he has implausible ideas about settling the country into a gold standard.
I feel like the only reason people like him is because he is, if nothing else, a man who believes in his principles. This is a rare trait in a politician. But just because the man wants to legalize marijuana does not make him qualified to be president.
Unfortunately, even less can be said of all the other candidates we have today. Current president included.