Where teacher voluntarily signed union membership agreement, First Amendment law did not invalidate ordinary contract principles that found the agreement was voluntarily entered into.The 7th U.S. Circuit Court of Appeals affirmed a decision by Judge John F. Kness, Northern District of Illinois.Ariadna Ramon Baro was an English-as-a-second-language teacher for Waukegan Community School District No. 60 during the 2019-2020 school year. As part of orientation, Baro attended a presentation by the Lake County Federation of …