My inclination is that art is a useful outlet for catharsis and morale but rarely as an act of politics per se. Of course art is political, naturally, but in terms of connecting art to formal acts of politics to changes in outcomes, no, I don't think so. The representation debate is so potent for me precisely because it is not about formal politics, it's about individual engagement with work and how people feel about themselves. I think art matters for how we consider ourselves in the world. Also, it's not to say that there isn't value in telling personal stories even if they are politically inert. If (let's be honest: when) DACA ends, I think there is value in telling journalistic or artistic takes on the undocumented and young. I just don't think such takes prevent deportation.
I feel the same way about, say, moral boycotts of companies. If you don't want conflict diamonds, don't buy them. If you want to buy union-made clothes, do so. If you want to avoid homophobic donations, don't eat Chic-fil-A, etc. But I think you have to do those things based on your own conscience, rather than the belief that that change will actually ripple through formal politics. The latter is unlikely and counterproductive.
Jonas Kyratzes (The Sea Will Claim Everything, Talos Principle)--who if memory serves me correctly is Greek and socialist and politically active--wrote about this yesterday:
http://www.jonas-kyratzes.net/2016/11/12/art-is-not-politics/
Here's a one-tweet summary of it:
I think his angle is more revolutionary than mine, in the sense that he seems to be refuting the idea that art is enough and angry that people want to mobilize through art rather than through formal organization and participation in the process. I think people gain great value in mobilizing through art, not because it affects change, but because it helps them cope with the situation they find themselves in.
But I think if you want to resist politics you disagree with, the best way to do so is through formal politics. Take back city councils, state houses, governorships, the house, and senate, work on ballot initiatives, organize a union, etc.