no one can live a full/joyful life if they are denied freedom
Explanation:
the author describes the outside world in the first few stanzas, and we learn that the bird beats its wings because it wants to escape the cage. the bird's song was a cry for help as it said "is not a carol if joy or glee"
Texas V. Johnson was a case in which the supreme court ruled that burning the flag was constitutionally protected by our first amendment rights (freedom of speech)