The correct description of the similarity in the Supreme Court's decisions in Tinker v. Des Moines and Texas v. Johnson is:
Wearing black arm bands and burning an American flag were both protected as forms of political symbolic speech.
In both cases, the Supreme Court held that these actions constituted symbolic speech that is protected by the First Amendment, even though they were offensive to some individuals. Tinker v. Des Moines affirmed that students do not "shed their constitutional rights to freedom of speech or expression at the schoolhouse gate," while Texas v. Johnson affirmed that flag burning is a form of political expression that is protected under the First Amendment.