In this case, definitely petty

This is revolting misconduct on the part of both the teacher and the police:

A Florida student is facing misdemeanor charges after a confrontation with his teacher that began with his refusal to recite the Pledge of Allegiance and escalated into what officials described as disruptive behavior.

The student, a sixth-grader at Lawton Chiles Middle Academy in Lakeland, Fla., east of Tampa, refused to stand for the pledge in the Feb. 4 incident, telling the teacher that he thinks the flag and the national anthem are “racist” against black people, according to an affidavit. The teacher then had what appeared to be a contentious exchange with the boy.

If living in the United States is “so bad,” why not go to another place to live? substitute teacher Ana Alvarez asked the student, according to a handwritten statement from her.

“They brought me here,” the boy replied.

Alvarez responded by saying, “Well you can always go back, because I came here from Cuba, and the day I feel I’m not welcome here anymore, I would find another place to live.” She then called the school office, as she did not want to keep dealing with the student, according to the statement.

Over to you once again, Justice Jackson:

It was said that the flag salute controversy confronted the Court with

the problem which Lincoln cast in memorable dilemma: “Must a government of necessity be too strong for the liberties of its people, or too weak to maintain its own existence?”, and that the answer must be in favor of strength. Minersville School District v. Gobitis, supra, at 596.

We think these issues may be examined free of pressure or restraint growing out of such considerations.

It may be doubted whether Mr. Lincoln would have thought that the strength of government to maintain itself would be impressively vindicated by our confirming power of the State to expel a handful of children from school. Such oversimplification, so handy in political debate, often lacks the precision necessary to postulates of judicial reasoning. If validly applied to this problem, the utterance cited would resolve every issue of power in favor of those in authority, and would require us to override every liberty thought to weaken or delay execution of their policies.

Government of limited power need not be anemic government. Assurance that rights are secure tends to diminish fear and jealousy of strong government, and, by making us feel safe to live under it, makes for its better support.

[…]

It seems trite but necessary to say that the First Amendment to our Constitution was designed to avoid these ends by avoiding these beginnings. There is no mysticism in the American concept of the State or of the nature or origin of its authority. We set up government by consent of the governed, and the Bill of Rights denies those in power any legal opportunity to coerce that consent. Authority here is to be controlled by public opinion, not public opinion by authority.

The case is made difficult not because the principles of its decision are obscure, but because the flag involved is our own. Nevertheless, we apply the limitations of the Constitution with no fear that freedom to be intellectually and spiritually diverse or even contrary will disintegrate the social organization. To believe that patriotism will not flourish if patriotic ceremonies are voluntary and spontaneous, instead of a compulsory routine, is to make an unflattering estimate of the appeal of our institutions to free minds. We can have intellectual individualism and the rich cultural diversities that we owe to exceptional minds only at the price of occasional eccentricity and abnormal attitudes. When they are so harmless to others or to the State as those we deal with here, the price is not too great. But freedom to differ is not limited to things that do not matter much. That would be a mere shadow of freedom. The test of its substance is the right to differ as to things that touch the heart of the existing order.

If there is any fixed star in our constitutional constellation, it is that no official, high or petty, can prescribe what shall be orthodox in politics, nationalism, religion, or other matters of opinion, or force citizens to confess by word or act their faith therein.