At Post Partisan this afternoon, I wrote about the news of the demise, or maybe demise, or something, of Ron Paul's campaign. Mostly, I thought it wasn't really a big deal, in that I suspect his actual campaign will continue more or less unchanged. If you're interested, however, I'd recommend Molly Ball's reported piece, which I saw only after I sent in my post. What she has that I didn't know was that, at least according to her sources, the Paul campaign hasn't been happy with the over-the-top demonstrations and, to some extent, conspiracy theorizing among many Paul activists -- as seen in Arizona over the weekend.
Has Ron Paul changed the Republican Party with his presidential runs? I think on the Fed, yes. On the rest...I really don't see much. There's some adoption of positions out of convenience, but I doubt it will last. I don't think the Paul campaign has made even a dent on foreign policy or civil liberties. Of course, that's just my impression; we'll see the real results in the future.