Under the First Amendment of the US Constitution, freedom of expression is protected. Citizens have a right to wear what they want, or nothing at all, because it is a form of expression, protected by the constitution. People have the right to express themselves and be protected by the US constitution.
Repeal all local and state laws that bans Against Naturism/Nudism. And let All Americans choose their own Lifestyles. This is the Land of The Free, Right? There is No Federal Law, No Constitutional Amendment against this. And it does Protect Americans Human Rights and Freedoms. Remember when Streaking at a sporting event was a time Honored Tradition?
I do think it falls under freedom of expression. Also, simply the ability "Pursue happiness" (yes I know that;s the Declaration of Independence but it still expresses the founders' feelings). If it were a violent crime this would be a different story, but who is harmed by this? The children? Children only take offense to it because the adults tell them they should, naturally, they would have no problem and it wouldn't scar them. If anything, it would give them a healthy image what what a human actually.
Nudity is constitutional simply because the constitution doesn't prohibit nudity. Also it's a human right and a natural right. In reality your going to see nudity from other people regardless it's part of life. Nudity is not offensive. People try to make it offensive and nudist colonies take money. Forcing someone to pay for the right to be naked is unconstitutional plus if you don't own clothes nudity ban doesn't apply to you for the same reason unconstitutional to force someone to spend money. Part of being an adult and parenting is when your kid sees another person walking done the street naked you explain. To them being naked isn't bad and then explain your opinion and teach your child your view. In America parents don't want to parent. Human Rights are protected.
The subjectivism of interpretation complicates things. With that said, the Constitution says nothing about nudity. It does not support it, nor does it prohibit it. Since this is the case, we have to look at other areas of the Constitution to figure out if nudity violates any part of it. The Constitution is a document that aspires to maximum Liberty as long as no one's rights our violated. Since nudity does not violate anyone's rights and is closer to freedom, we have to conclude nudity's constitutionality.
As others have mentioned, it can also be argued that nudity is a right protected by the first amendment. Any attempt to prohibit someone's nudity, is unconstitutional and at odds with Liberty. And besides, nudity is natural. Even nature supports it.
Yes, public nudity could be considered constitutional, but even if something is considered constitutional, that doesn't mean that an individual has no responsibility to exercise discretion. For example, freedom of religion exists, but most people will agree that preaching in the streets is not acceptable. Another example is the reality that even though the constitution allows for firearm usage, using a firearm in public is generally illegal.
I know that US constitution has accentuate that everyone has the freedom to do anything which called Freedom of Expression. Nevertheless, there is a limit for the things that we want to do. If not, our society will become chaos as there are nothing rules or regulations can control people.
The constitution was written to provide the people (citizens) the ability to speak out and effect changes in government, without fear for their lives and well-being. No, I wasn't there when it was written, but I'm pretty sure the writers of it had no idea of a future where every moral behavior they took for granted would be challenged. Public nudity is in the realm of morality, not free speech. Just another example of people trying to rebel against anything they can think of, and shove it down everyone else's throats. There are plenty of nudist colonies, beaches etc to accommodate these people, not to mention their own homes. So when they go outside of those areas to force it in public, free speech might be the excuse they use for it, but it's not really about that at all.