Let me rephrase that. The legitimate power.
Government does legitimately have that power. Otherwise, we would have the right to go nude anywhere we want.
The question is, "Where to draw the line?" Most agree total nudity in public areas is too much.
I don't care if someone's underwear is peeping out - but I HAVE seen teenagers who were wearing pants with half or more of their butt crack showing - in a McDonalds. That was repulsive.
Should it have been illegal? Don't know...I would as soon see a law preventing the sale of spandex in clothes above a certain size, or a requirement that bare midriffs only be allowed if there are no rolls of fat showing.
Unwise law? Perhaps.
Unconstitutional? No.