“Imminent” and “lawless” are the operable terms. I can legally opine to my hearts content about how it could hypothetically be a good idea to rob every bank in New York but if I’m not inciting anyone to actually specifically do so, that’s not legally imminent. Likewise, if I propose a series of constitutional amendments, the net effect is to legalize or legally mandate some sort of atrocity, there’s a case that I’m not even technically advocating for lawless action.
But the primary value of Brandenburg v. Ohio was in rejecting the early 20th century jurisprudence based on the “clear and present danger” status set by Schenck v. United States.
Schenck and the rulings that followed it gave legal cover to imprison people who advocated for draft resistance as well as effectively banning Communist parties (on the theory upheld in Whitney v. California that communism entails the violent overthrow of the US Constitution). Brandenburg and its successor cases effectively overturned that entire line of legal reasoning in favor of an extremely strict standard that only allows the government to prohibit things like inciting mobs or engaging in criminal conspiracies.
But the primary value of Brandenburg v. Ohio was in rejecting the early 20th century jurisprudence based on the “clear and present danger” status set by Schenck v. United States.
Schenck and the rulings that followed it gave legal cover to imprison people who advocated for draft resistance as well as effectively banning Communist parties (on the theory upheld in Whitney v. California that communism entails the violent overthrow of the US Constitution). Brandenburg and its successor cases effectively overturned that entire line of legal reasoning in favor of an extremely strict standard that only allows the government to prohibit things like inciting mobs or engaging in criminal conspiracies.