As for advocating for organizing at your workplace being unfair to your coworkers: they are not required to join, but as union shops consistently pay better, are safer, and provide better protections against arbitrary firing, I would still be comfortable advocating for those conditions for my coworkers.
https://en.wikipedia.org/wiki/Closed_shop#United_States
As for advocating for organizing at your workplace being unfair to your coworkers: they are not required to join, but as union shops consistently pay better, are safer, and provide better protections against arbitrary firing, I would still be comfortable advocating for those conditions for my coworkers.