In the 1988 case Texas State Teachers Association et al. v. Garland Independent School District et al., the U.S Supreme Court ruled that a public school district could not deny employee organizations access to its internal mail system while granting such access to other groups, as it violated their First Amendment rights. The Garland Independent School District had allowed certain community and professional organizations to use its inter-school mail delivery service but denied this privilege to teachers' unions including the Texas State Teachers Association (TSTA). In response, TSTA filed a lawsuit claiming violation of their free speech rights under the First Amendment. The court held in favor of TSTA stating that by allowing selective access, the school district was engaging in viewpoint discrimination which is prohibited under the Constitution's guarantee of free speech.

In the dissenting opinion for Texas State Teachers Association v. Garland Independent School District, Justice Blackmun argued that the majority's decision was a departure from established precedent regarding public employees' First Amendment rights. He contended that by allowing school districts to restrict teachers' speech on matters of public concern without demonstrating any actual or potential disruption caused by such speech, the Court had effectively undermined teachers’ constitutional right to free expression. Furthermore, he expressed concerns about the implications of this ruling for academic freedom and open discussion in schools. He believed it could lead to an environment where educators would be hesitant to voice their opinions out of fear of retaliation from administrators - a situation detrimental not only for teachers but also students who benefit from exposure to diverse perspectives and critical thinking skills fostered through open dialogue.