All art CAN be political... and even if it wasn't originally created so by the artist in question, it can still be taken and utilized in such a way by others, or perceived as political when it was never intended to be.
That old line about "in the eyes of the beholder" rings true here in ways people can't possibly conceive of when they're in the act of creating; something completely abstract can become associated with any issue and thenceforth seen to represent that issue, even when it originally had nothing to do with it.
Or, as the case of Springsteen's 'Born in the USA' and then-President Reagan showed, the point can be missed completely and the message becomes warped by those who don't understand, or choose to selectively interpret what they're hearing or seeing. Most of you are probably too young to remember what I'm talking about there...
Conversely there is also such a thing as trying too hard to make something a political anthem or theme...