For every idea of his that is acceptable or even attractive to any particular group in American politics, he has two that said group would find absolutely unacceptable. He doesn't want to become president bad enough to abandon his principles, which of course is one of the things so many people admire about his candidacy - but it also means he's not actually a candidate to be President. He just wants to promote his ideas, and he certainly has a lot more influence this way than he'd have through his House seat alone.

So to sum up, it's not gonna happen, and you wouldn't like it if it did (although Paul becoming president would definitely be one of the most exciting political experiments in recent history: how much would he actually change, and what would the consequences be? It's just only a madman would want to volunteer his country for said experiment.)