> Unions aren't a monopoly they're a democracy. After a democratic vote, the minority has to accept what the majority wants.
OP is repeating a lot of anti-union propaganda, but this one point is true, which is evident if you look at how unions in other countries work.
In many European companies, it's commonplace for workers in the same company to have a choice of which union to represent them, so two different workers may be represented by two different unions. That's essentially unheard-of in the US, where unions almost exclusively claim majority representation.