The right to join a union or any other organization is a right guaranteed by the United States Constitution. A right to work law does not infringe on that right but protects workers from being compelled to join or support a union.

Organized labor wants to convert the right to join into an obligation to join.

If that policy were extended to other first amendment rights such as the right to worship, it would become the obligation to worship. That is not an America that the authors of the Constitution would recognize.