Practically every law ever written can be construed as 'unconstitutional' ... as it always takes away one freedom or another, for either the actor or the actee.
We accept some laws much easier than others, and generally accept the laws that protect one party from another, usually because it's convenient or has no affect on our individual lifestyle.
A law might be ethical, moral, or protective, but it still takes away the freedom of one person to perform an action.
For example: Laws against robbing a person. Takes away the right or the ability for one party to rob and steal from another. It's not moral, it's not ethical, it's not even nice, and it's not always successful, but some individuals believe it's OK to rob someone -- culturally, we believe that's a wrong act.
Some societies feel it's a brave act, or a necessary act, or a proper act, to steal from another person (in a neighboring tribe, for example) ... so, we might believe it's wrong, but not every culture in the world believes as we do ...
Laws come about because more people believe one way, or less people another. It's the enforcement that makes a law apply ... we can't regulate behavior, we can only penalize people after the fact, and usually that forces compliance, not always because it's a law or that people believe in it.
Laws are generally accepted because the penalty is greater than the gain if you break it. If you rob someone of five hundred dollars - and the penalty is five years. That's not a good value exchange for the behavior.
