Right to work is completely different. Right to work says that employees are not compelled to JOIN a union in the first place. I have never heard of a union where some employees are required to pay dues and others aren't (and in fact, I have never heard of a union where employees pay no dues at all.)
How would selective dues even work? If the union requires dues you either pay and are represented or you don't join (go work somewhere non-union). I'm struggling to figure out where it would even make sense to be selective.
