In which case did the Supreme Court signal the LEAST protection for commercial speech under the First Amendment?

Question

Quizplus · Accepted Answer

In Valentine v. Chrestensen, the Supreme Court held that purely commercial advertising, such as advertising for a commercial venture and not protected by the First Amendment. This case marked a departure from the previously recognized protection of commercial speech under the First Amendment. Therefore, it signaled the least protection for commercial speech under the First Amendment.

In Which Case Did the Supreme Court Signal the LEAST