Anybody who was/is as rich as he was even when he started is inherently a part of the political establishment, especially so when you don't just stay low and mind your own business (see: Bezos' impact on unions in the US)

He wasn't when he ran; he is now; neither fact matters at all for the point, which is that the message of the art (the songs being used in campaign events) was being misused / destroyed, by direct testimony of the artists. Same as Gibson saying he doesn't approve of how his cyberpunk message is being used.