Not that I agree with the concept of the law in question, a private airline does have the right to require that you present any ID of their choosing to fly on t

Not that I agree with the concept of the law in question, a private airline does have the right to require that you present any ID of their choosing to fly on their planes. They have the right to refuse you if you choose to not follow their rules. There is room for debate on whether the airlines should be creating their rules based on laws for the TSA that are then not publicly displayed. But the thing is, if the law pertains to the airlines and not the public then that's the sticking point. Let's say that the lawmakers had decided that said law involved national security and that gives precedent to keep the law secret to those it does not directly affect. The law, which we haven't seen, likely only pertains to the airlines directly and not the passengers. The airlines are informed of the law that tells them they are required to request ID. It's likely you couldn't even sue in that case because you wouldn't have standing. The thing is, this type of law likely no longer applies. These days, in the U.S. at least, you typically do not have to show ID at the counter to get your tickets or at the gate to get on the plane, which was done in the past. They might ask to verify you should be getting the tickets you are requesting, but likely they won't resist much if you refuse. Recently you only need a credit card to identify yourself to get your tickets from the automated kiosk. Now you have to show ID to a government agent at the security gate to get past. That's the rub, they are now requiring that you show ID to get past the security gate, not to get on the plane. You are not being restricted from traveling by not showing ID, you are being restricted on entering a certain part of the airport for not showing ID. If you can get past the security gate, you are free to enter the plane. Therefore, you cannot claim the government is preventing your right to travel for refusing to show ID at all. They're just not letting you go down a certain hallway in a building for refusing to show ID. Any law can be written to do anything you want that easily passes Constitutional muster if you think things through.