Proponents of unions advance the classic free-rider argument for compelling non-union employees to share in the cost of collective bargaining. Public unions are usually legally required to provide services to non-member employees. Because of this, if employees did not pay fees to offset the costs of these benefits, then they would be exploiting the people who did pay. This would effectively be stealing. This argument is morally compelling, and this can be illustrated by an analogy.
Imagine that a Lunch Group was formed by people who went to lunch together and this group provided lunch and other benefits in return for a membership fee. Now suppose that a law was passed that required the Lunch Group to pay for the lunches of anyone who was in the same restaurant when they had their lunch. While this would be a great deal for freeloaders, it would not be fair for the Lunch Group. As people could get the benefits of the Lunch Group without contributing, the group would probably disband as paying members would have little incentive to remain because the free riders would be exploiting them.
Naturally, some free riders might argue they are entitled to the free lunch, but that they should not contribute because they do not like the other benefits and disagree with some of the views of the group members. They just want their free lunch. This is analogous to the free speech argument advanced in favor of not paying the union fees: the employees want the benefits of the union, but do not want to pay for them. They justify this by claiming that they do not agree with the political views and activities of the union. However, this is an absurd argument.
The no-free lunch reasoning is usually a favorite of conservatives. For example, it is a common conservative position that people who can work should work rather than “freeloading” on welfare. They criticize people who exploit the system as free riders. This principle should apply to public unions: if free riding on others is morally wrong, then free riding on a public union is morally wrong as well.
Fortunately, there is an easy solution to the problem, and one often endorsed by conservatives: workers should be free to join the union or not and they should be free to pay the fees or not. But, if they elect to not pay the fees, then they should receive none of the benefits. Just as a business is not required to provide free stuff to people just because they want it, the same should apply to the unions as well.
If unions are compelled to provide services to non-union members, then the law must also compel them to pay their fair share. Otherwise, the state would be mandating the equivalent of free lunches, something that conservatives rail against. Except when it comes to busting unions. After all, an effective way to destroy a union is to compel it to provide services for free. This will encourage free riding and will deplete union funds—something that would please most conservatives. It is thus somewhat ironic that some conservatives use a tactic against unions that explicitly violates a professed principle of conservatives. But expecting consistency or any consequence from inconsistency has proven foolish. As has expecting principles.