Yep. Somewhere I read that he stayed a Republican, but then a few minutes ago I read that he wrote an angry letter condemning the GOP.
http://www.lp.org/blogs/staff/lp-monday-message-10-ron-paul-questions3. Is Ron Paul a member of the LP?
While Ron Paul is a Republican Congressman, he is also an Honorary Lifetime Member of the Libertarian Party, and he will remain so unless he requests to have his membership terminated...
Once a libertarian, always a libertarian, I say.
One can never go back.