McCain is a poor choice, but the Republican field was just awful (with the exception of Paul of course). They didn't have anyone better to pick.. they still don't (from their perspective).
Guliani was never going anywhere -- he's pro-choice and has a seriously checkered past.
Romney's a mormon, which hurt him. He also flip-flopped on abortion and has the aura of a used car salesman. Not the best. All the money in the world can't make up for some things.
Huckabee's great, for those who love him. For everyone else, he's just not Presidential material. He has no foreign policy credentials, for example.
Thompson was better at playing a President on TV. They tell him to "act like yourself" and he can't quite figure that one out.
And Paul. Paul. The most conservative man on the stage of these six. Probably the Republican's best chance to win. But they don't care. Even if the Republican party knew 100% that McCain would lose and Paul would win in November, they would stick with McCain. They care more about maintaining control of their party, no matter if it continues to shrink or if they ever win an election again.
Until we replace the Republican leadership and change the fundamental direction of the party, someone like Paul, a true conservative, unfortunately has no chance of winning the nomination. It's sort of a catch-22, but I think Paul's candidacy has gone a long way, probably more than we realize, towards achieving that end. And we should continue to strive to achieve it, even though it's probably impossible, at least in 2008 anyway. I'm sure many said independence from England was impossible, too. But you continue to work at it until maybe it doesn't quite seem so impossible. You keep working, until, hey it might very well happen!