Here's an article I found on CNN.com
Ron Paul ponders politics, 2012 run - CNN.com
Paraphrasing the article, Ron Paul basically does not think he can win a Presidential election but he will run nonetheless.
He advocates "limited government and the need for government officials to follow the Constitution," which is what a lot of the Tea Party folks are advocating which would make him a good poster child for their movement. These are also principles that the GOP claims to champion.........in theory.
"Paul does express some skepticism that GOP promises of reforming Washington and cutting government might just be talk."