In non-Right to Work states, sincere religious objectors may have the right to redirect the entire union fee from the union to a nonunion, nonreligious charity.
To read a copy of "An Employee's Guide--To Union Dues and Religious Do Nots," which describes how to obtain as accommodation of an employee's religious beliefs against joining or financially supporting a labor union, click here. This guide is copyrighted 1996, National Right to Work Legal Defense Foundation, Inc.
If you work in a Right to Work state, you have a right not to join and not to financially support unions. If you would like to see a list of the 24 Right to Work States, click here.