As for closed shop:
https://en.wikipedia.org/wiki/Union_shop#United_States
It's illegal, so's the similar "union shop", and you can opt out such that you still pay dues but they may only go toward collective bargaining activities and services to members, which appears to solve this "I'm being forced to support the only viable political party that wants to make anything whatsoever better" problem. Maybe leaving others, sure, but this issue's... not an issue. Unlike employers. I can't sign a piece of paper banning them from using profit derived from my labor for political activity.
But the thousands of companies I could work for have healthy competition and diversity of approach to issues. An industry-wide union has no competition and no diversity.
> Maybe leaving others, sure, but this issue's... not an issue.
Say you were a Green supporter, and had a strong conviction against military intervention. How would you feel funding a union leadership that campaigns for Labour, following Iraq?
Wow, I can tell you evaluate statements in an unbiased manner. What happens when you realize the idea of "better" turns out to depend on some pretty big assumptions that you no longer believe are true? Additionally, if the only two "viable" political parties are abhorrent like the ones in the US, giving any money to either of them is still morally fucked up if you truly disagree with them and vote 3rd party.
At any rate, the two-party thing's how our (the US's) system's structured. It stabilizes there. A third party replacing one of the big two, as has happened occasionally in the past, would assuredly acquire a good bit of distasteful cruft along the way. Effective political action revolves around trying to help a 3rd party replace one of them despite that likely outcome (and accepting an even smaller voice in policy than most voters have, in the meantime); participation in one of the big two parties themselves (much, much large effect than just voting in elections, though still usually tiny); or working to reform our system to break the two-party stability point. Or some combination of those things.
It seems that some unions have shifted from representing employees in negotiations to representing a profession in all respects. I believe that's contrary to their original purpose and dilutes both their support and their credibility as simply advocating for the worker.
What do I do when there is an industry-wide closed-shop union, as some people seem to want?