Idealogue n. : One given to fanciful ideas or theories; a theorist; a spectator.

Example:
Is OBAMA a rigid liberal Idealogue who insists on moving us to SINGLE-PAYER with Government-Run Public Option?

Taxonomy
ideologue, Merriam-Webster Online Dictionary, Dictionary, webster, logue, Word Games, Webster Online Dictionary with audio pronunciations, thesaurus, glossary, english, language, ESL, ideo, Etymology, back-formation, idéologie, idealist, blindly.

Defination from the web:
ideologue from the Merriam-Webster Online Dictionary with audio pronunciations, thesaurus, Word of the Day, and word games. ... Etymology: French idéologue, back-formation from idéologie. Date: 1815. 1 : an impractical idealist : theorist ...