alt Hacker NewsYou are free to leave. You aren't free to go wherever you want. You aren't free to go into the employee areas, or out onto the runway. If you don't clear security, you aren't allowed in the secure portion of the airport. Not allowing entry into an area is not "detaining you from moving forward".
If the government is requiring the property owner to submit to TSA, that's a public act and not a private one, which means it is bound by the bill of rights and most importantly the 4th 5th and maybe even 6th amendment. The government cannot punish you for exercising your rights by refusing you to move forward into the private place you could otherwise lawfully go. If you can't go to the employee area, that's because certain individuals are trespassed from going there from the private owner, not because the government is forcing it. If you can't go to the boarding area, because of the TSA by public act strong arming the property owner, that is not an act of the private owner, and if it's done because you refuse to answer questions it is a violation of your rights.
The ruse here is to pretend like the property owner is agreeing with TSA because TSA forced them to this agreement by government act. But that is just the government trying to have their cake and eat it by forcing someone to do something and then pretending it is a private act which isn't bound to the constitutional right to not have to answer additional questions.