He's gone very far. He'd be a far better President than any of the other guys, but give him credit, he's done more for libertarianism than anybody else in the last 20 years. Consider:
1. He's raised a lot of money that's now being used to help libertarian candidates win. Think Rand Paul. There wouldn't BE a Rand Paul if not for the 2008 primary.
2. He's spurred the creation of several activist organizations, (like YaL, CfL, etc.) some run by himself, others only inspired by his example, that help candidates and issues throughout.