The U.S. Supreme Court's 2018 ruling in Janus v. American Federation of State, County & Municipal Employees, which overturned precedent set by Abood v. Detroit Board of Education, was an example of the Supreme Court:

1. following the doctrine of stare decisis
2. not following the doctrine of stare decisis
3. applying the void for vagueness doctrine
4. applying both the void for vagueness doctrine and the overbreadth doctrine.