Mr. Mitchell misses the point of Right to Work. The employer can still chose to have a union shop. But each employee can choose to be part of the union or not. The employer does not have to negotiate separately with the non-union employees. Nor does he have to treat them differently. It does not change the Employer-union relationship other than not obligating employers to fire non-union employees.
Many people point out that if someone doesn't want to be part of a union, get a different job. Why should I get a different job simply because 50% +1 of the shop want a union? If I do not want a union, the union has not done a good job of convincing me they need to be in my shop.
Right to Work laws force unions to compete for workers.