I don't know what you mean by "full patdown treatment", but they're absolutely tracking down your information in databases and interviewing you about it. See replies to:
It's not just a patdown. They take you to a phone booth that has a direct line to some portion of the FBI IIRC, and they ask you a bunch of questions to confirm your identity. At least this is what happened to me about ten years ago when I lost my wallet in a different state and needed to fly home.
... and the law in most states requires only that you give your name and possibly your DOB to the authorities upon detainment. So as a purely academic exercise, what can they even do if you refuse to answer beyond that? Obviously in practice they will fuck with you or just straight up violate the constitution, but theoretically I'm unsure how they can continue to seize you after that.
They can't detain you (if you're not otherwise some kind of suspect, and you're not trying to assault them or sprint past security or anything), but they don't let you fly.
... if you aren't detained you are free to go. And if you are free to go, you are free to stay, unless the property owner has trespassed you. TSA doesn't own the airport, at least in my state. So how can they trespass you from the airport or otherwise continue to detain you from moving forward?
I mean, I know you're right, and I know you will always lose if you try, but I don't understand the legal basis.
You 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.
Presumably the airport or airline has agreed to (or would agree if asked to) have TSA decide whether you are “free to go that way, towards the airplanes”.
You are already free to go that other way (towards the street), but not necessarily free to go the way you want.
As far as I can tell, a person is free to go if they refuse screening: They won't be getting on a flight, but they can just leave. There's no detainment involved in this process.
Whether they can then elect to stay is a different matter, I think.
But so what? How long would a person have to stand in a screening area before someone who properly represents the ownership of that space shows up and authoritatively tells them to GTFO, do you suppose?
https://news.ycombinator.com/item?id=46864182
It's absolutely not just enhanced physical screening.