Now naturally an employer's not going to want to agree to that. But he's not going to want to agree to higher pay or more vacation days either. That's why it's a negotiation. A right-to-work law is a law banning employers from making that concession.
The impact, obviously, is to make it hard to form strong unions in a given jurisdiction and thus make it a more business-friendly jurisdiction. But note that this same trick works across the board. You could just ban pay raises in general. Any one firm, after all, faces a dilemma. On the one hand it would be more profitable to pay people less. On the other hand, it's also unprofitable to have everyone quit to go work for some other higher-paying company. So a law against pay raises would make everyone more profitable, spurring crazy business investment and job creation. Except nobody does that because it would be (a) insane and (b) obviously unfair. And yet the proponents of right-to-work laws are generally exactly the people most inclined to stand up for freedom of contract under other circumstances.It is very odd that right to work has become a libertarian position. Employment contracts require both sides to be able to bargain freely. In an "Adam Smith" nation of shopkeepers, where an employee is bargaining with a single business owner there is some sort of sense to this arrangement. But business has a lot of money and power relative to workers. Why would it be illegal to try and pool resources on the worker side when it is fine for a pool of owners to pool resources by forming a corporation? Do we honestly think that corporations don't also try and influence the political process via lobbying and donations just as unions do?
Wage controls are also not without precedent but at least the contradiction is more immediate and obvious. Now, I am not a libertarian but I would really like to know how this sort of ban on organizing groups is a loss of freedom. Sure, you could end up belonging to a group you did not intend to join. But we don't ban corporate takeovers because the workers never consented to being a part of the acquiring company, do we?