In Arizona it is illegal for an employer to coerce or compel a person not to join a Union...

23-1341.Invalidity of employment agreement not to join, become or remain member of labor or employers' organization.Every undertaking or promise made, whether written or oral, express or implied, is contrary to public policy and void and shall not afford any reason for granting legal or equitable relief, when constituted or contained in a contract or agreement of hiring or employment between an employer and an employee or prospective employee, whereby:1. Either party to the contract or agreement undertakes or promises not to join, become or remain a member of any labor organization or of any organization of employers.2. Either party to the contract or agreement undertakes or promises that he will withdraw from the employment relation in the event he joins, becomes or remains a member of a labor organization or of an organization of employers.

23-1342. Compelling or coercing another not to join labor union as requisite to employment; classification A person who coerces or compels any other person to enter into an agreement, either written or oral, not to join or become a member of a labor organization, as a condition of the other person obtaining employment or continuing in the employment of such person, is guilty of a class 2 misdemeanor.

Arizona is a Right to Work state, the Union recognizes all workers right not to join a Union.

23-1302. Prohibition of agreements denying employment because of nonmembership in labor organization No person shall be denied the opportunity to obtain or retain employment because of nonmembership in a labor organization, nor shall the state or any subdivision thereof, or any corporation, individual, or association of any kind enter into an agreement, written or oral, which excludes a person from employment or continuation of employment because of nonmembership in a labor organization.