Final answer:
Abortion a more important issue, cannot be clustered with the subtopic of a constitutional amendment prohibiting flag burning as it introduces a separate issue. (option D is the correct answer).
Step-by-step explanation:
The point that could not be clustered under the subtopic of a constitutional amendment prohibiting flag-burning because it is excessive is D. abortion a more important issue. This option does not align with the specific topic of flag desecration and its constitutional implications but rather introduces a separate, controversial issue of abortion rights.
In contrast, options A, B, and C directly relate to the debate over flag burning, discussing its priority compared to other issues, its prevalence, and the reactions it prompts.
Throughout American history, the First Amendment has been fiercely defended to protect free speech, including symbolic speech such as flag desecration. As detailed in cases like United States v. O'Brien and the responses to federal laws like the Flag Protection Act, the Supreme Court has consistently maintained that symbolic speech is protected, a stance which reinforces that any amendment prohibiting flag-burning would be excessive and contrary to long-standing constitutional principles.