I have no idea what it takes to win a wrongful termination lawsuit. I assume it would be next to impossible to prove.
However, Right to Work has to do with one thing and one thing only; whether or not you can be compelled to join a union as a condition of employment. In Michigan for example, before they adopted Right to Work, you could be compelled to join the union if the shop was organized. No union, no job. Now that they are Right to Work you cannot be forced to join a union to get a job. That is the only thing that Right to Work deals with.
You're probably thinking of At Will employment, which is something else all together.