speech was not specifically outlawed by the legislature. Brandeis and Holmes again promoted the clear and present danger test, this time in a concurring opinion in 1927's Whitney v. California decision. The majority did not adopt or use the clear and present danger test, but the concurring opinion encouraged the Court to support greater protections for speech, and it suggested that "imminent danger"a more restrictive wording than "present danger"should be required before speech can be outlawed. After Whitney, the bad tendency test continued to be used by the Court in cases such as Stromberg v. California, which held that a 1919 California statute banning red flags was unconstitutional. The clear and present danger test was invoked by the majority in the 1940 Thornhill v. Alabama decision in which a state anti-picketing law was invalidated. Although the Court referred to the clear and present danger test in a few decisions following Thornhill, the bad tendency test was not explicitly overruled, and the clear and present danger test was not applied in several subsequent free speech cases involving incitement to violence. The importance of freedom of speech in the context of "clear and present danger" was emphasized in Terminiello v. City of Chicago (1949), in which the Supreme Court noted that the vitality of civil and political institutions in society depends on free discussion. Democracy requires free speech because it is only through free debate and free exchange of ideas that government remains responsive to the will of the people and peaceful change is effected. Restrictions on free speech are permissible only when the speech at issue is likely to produce a clear and present danger of a serious substantive evil that rises far above public inconvenience, annoyance, or unrest. Justice William O. Douglas wrote for the Court that "a function of free speech under our system is to invite dispute. It may indeed best serve its high purpose when it induces a condition of unrest, creates dissatisfaction with conditions as they are, or even stirs people to anger." Dennis v. United States In May 1950, one month before the appeals court heard oral arguments in the Dennis v. United States case, the Supreme Court ruled on free speech issues in American Communications Association v. Douds. In that case, the Court considered the clear and present danger test, but rejected it as too mechanical and instead introduced a balancing test. The federal