People consider too many things "rights" these days in my opinion. Oh well, doesn't make it so.
I may have already posted this
Teacher's Unions/Collective Bargaining: Encyclopedia of Everyday Law
Constitutional Considerations Regarding Unions
The First Amendment of the BILL OF RIGHTS provides: "Congress shall make no law . . . prohibiting . . . the right of people peaceably to assemble." This right, as applied to the states through the Fourteenth Amendment of the Constitution, has been interpreted to give teachers and other employees the right to free association, including the right to join a union, such as the National Education Association or the American Federation of Teachers.
However, the Constitution does not grant teachers the right to bargain collectively with employers. This right is based on applicable provisions in state constitutions, federal statutes, or state statutes. Similarly, teachers do not have a constitutional right to strike, though other federal law or state law may permit teachers to strike.