How do you disentangle politics and economics here? Or, are you just claiming that unions are focusing on the wrong side of the equation?
If you want to improve conditions for workers, just say that you want to improve pay / $hr, increase break time by x min, and define xyz working conditions and have a detailed plan to support that. I've personally seen 0 unions pursue this approach... but have seen plenty advocate support for completely unrelated, purely political topics (e.g. voicing support for Palestine)