That Obamicon site saved me about three hours of photoshopping...
potentially, the power of the shepard fairey obama-hope was in its ironies: i personally did not know whether to read it as inspirational or scary, until fairey made clear that his purpose was purely obamania. how the mighty are fallen: fairey's "obey giant" stuff was notable for its combination of semantic repleteness and simplicity: it kept exceeding your grasp; or it seemed completely arbitrary, but somehow it was a political commentary too, bringing into play socialist realism, graffiti, pop art, etc. it was a propaganda poster. but what could it possibly be propaganda for? it was at play in the field of political aesthetics. then fairey imitated his own style without irony. he started marketing "obey" t-shirts at target. he decided to put his pointedly ambiguous art in the service of actual propaganda: really a bizarre re-appropriation, or a kind of paradigm postmodern moment. and you had to read the previous images differently. the "hope" poster sucked the irony retroactively out of the whole oeuvre.
Shepard Fairey is a talentless hack.