I suspect it works both ways. Art with an explicit political message (i.e. something sophisticated enough to be able to disagree with) is less likely to gain widespread appeal than something politically ambiguous.

I've recently been thinking about notorious graffiti artist Banksy lately, who's a pretty good example of this. He does have widespread appeal, in spite of his work being considered political, but his art doesn't present a coherent enough political stance for anyone to actually disagree with.