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.
The ID was purportedly required by the TSA, not by the airlines. And so cannot be justified on the right of the airline to set rules that they want as a private entity.
I totally agree, that's why I believe the requirement was shifted from the airlines' responsibility to the TSA directly. Now you are not being asked for ID to travel, you are being asked ID to pass a security gate.
> I totally agree, that's why I believe the requirement was shifted from the airlines' responsibility to the TSA directly.
No, it was shifted as part of the general shift of security responsibilities to the TSA so that the airlines (who don't have sovereign immunity) wouldn't be responsible for future security incidents, that would instead be the responsibility of the TSA (who does enjoy sovereign immunity except to the extent Congress chooses to waive that immunity.)
The ID was purportedly required by the TSA, not by the airlines. And so cannot be justified on the right of the airline to set rules that they want as a private entity.