Final answer:
The first test for the government to intervene in political speech was the "clear and present danger" test, not the Lemon test, which pertains to government involvement in religion. The "clear and present danger" test was primarily concerned with speech that could harm the nation's security.
Step-by-step explanation:
The first test for determining when the government may intervene to suppress political speech was not the Lemon test, but rather the "clear and present danger" test. This decision limited First Amendment rights to free speech if it imposed a "clear and present danger" to the security of the United States or its people. In the 1969 Brandenburg v. Ohio case, the Supreme Court found that only speech that constitutes a direct call or plan to imminent lawless action could be suppressed. Over time, tests regarding speech have evolved. Speech that is speculative or advocates for change without inciting imminent lawless action is protected.
Conversely, the Lemon test, from the 1971 case Lemon v. Kurtzman, evaluates laws related to government involvement with religion, requiring such laws to have a secular legislative purpose, not advance or inhibit religion, and avoid excessive government entanglement with religion. For the government to constitutionally limit speech, the law must be content neutral, serve a compelling governmental interest, represent the least restrictive means, and it cannot exercise prior restraint unless under extreme circumstances.