There are several good candidates, but let me throw my three cents (inflation and all...) for Ron Paul. Here's a few reasons why:
- His supporters are Committed (a lower-case "c" doesn't seem sufficient). Paul raises money and draws crowds almost literally without effort. He's a conduit completing an untapped circuit with a great deal of power, a power he seems a bit unsure how to use. Most of these people need no organization to turn out.
- His opponents' supporters are not committed. Oh sure, each candidate has their hard-cores, but no other Republican engenders nearly the intensity of support.
- He doesn't really have competition. Every time I go to a Paul event, someone asks him if he'd consider running as an Independent. The thing is, he already is in everything but name. His supporters are by and large not drawn from other candidates, they're people being drawn into a system they'd given up on. A surge by another Republican isn't going to hurt him much.
- Polls underrepresent him. I don't have proof of this, but given that Paul's supporters are largely outside the mainstream and obsessed with privacy rights, it's hard to imagine that a lot of them are picking up a lot of calls from pollsters.