Final answer:
The First Amendment does not protect speech that incites imminent and likely lawless action. Brandenburg v. Ohio clarified that only direct calls to immediate illegal activity are unconstitutional. The 'clear and present danger' standard from earlier rulings also contributes to understanding when speech may be limited.
Step-by-step explanation:
The legal standard in question is related to the First Amendment's protection of speech and when such speech may not be protected due to its potential to incite lawless action. Specifically, speech that is aimed at inciting lawless action that is both imminent and likely does not fall under the protective umbrella of the First Amendment. The Supreme Court's decision in Brandenburg v. Ohio set the precedent for this understanding, stating that only speech that incites immediate illegal activity is devoid of constitutional protection.
Furthermore, earlier cases such as Schenck v. United States and Chaplinsky v. New Hampshire also help define the boundaries of protected and unprotected speech under clear and present danger and fighting words doctrine, respectively. It is crucial to differentiate between mere advocacy, which is protected, and direct calls for immediate violence or illegal activities, which are not protected.