Thta's the responsability of the participants. It sounds like they've been complacent and they allowing people to represent them who do not represent them.
No, it is the responsibility of the laws surrounding unions in USA. They give ample of protections ensuring you can't easily oust or change bad unions. Even worse the left is championing anti worker laws like banning "right to work", a right that everyone in EU has which protects workers from bad unions, but somehow in USA "right to work" is anti union.
A union security agreement is a negotiated contract, not something to be universally required or prohibited by law. Its purpose is to prevent free riding of both the company and potentially non-union workers. When such a contract is made with a company, employee contracts with unions become part of the cost of working there in exchange for the exceptionally better working conditions created by the union. To describe prohibition of such contracts conferring such concrete benefits to workers as "anti-worker" is disingenuous at best, especially considering "right to work" is a euphemism for union busting which is precisely why such battles are waged in the abstract rather than tied to to the material conditions of workers.
