http://www.thinktankwatch.com/2012/05/will-obama-join-council-on-foreign.html
I’ve seen it other places though. Back in the early ‘00’s.
Membership is 5years IIRC so he may have been a member in the past but is no longer a member now.
He certainly qualifies as the ‘loyal opposition’ though.
It's a little hard to determine how credible the source is, given that they list Limbaugh as a CFR member...but he's not on the current roster.
I'm curious. You use the term "loyal opposition" as if it might be a pejorative. Is that how you mean it?