Would that be the former Green Party candidate Rev. Elston McCowan who had announced his candidacy for Mayor of the City of St. Louis (in 2008?)? The one who lead a march in protest of "Israel’s excessive bombing of the Gaza Strip"?
See this page and this page from google's cache.
(I didn't have the courage to try the guy's facebook page or any of the other pages that come back to a search on "Elston McCowan", including an endorsement by socialistorganizer.org and a myspace video - after all, you never know what you might catch by going to such places)