Customs law? You have an absolute right to return to the country as a citizen. You do not have an absolute right to bring whatever you want into the country, even as a citizen so they can search your belongings to see if you are carrying contraband. It's a different set of rules than if you're just on the street already in the country, crossing a border customs has a lot of leeway

I'm not saying that I agree with it, it's just the way it is