No 4th amendment issue. They tell you that you have been selected for special screening, you can decline and leave the secured area.
Not true. And they have a court case to back it up. Once you start the screening process, you cannot decide to stop. Even if they don't notify you that you will be nuked until you get past the point of no return.
Try to decline, and they will call the cops.
It would be most productive if you directed your anger at the politicians that brought us the TSA rather than at the individuals who took a goverment job with federal seniority and benefits.
Look at the BARR program. Political action by the GA caucus reversed a political decision made by the class warriors in the administration.
Not going to happen here. THe politicians are afraid that they will look "soft" on terrorism & it will be used against them. Most of the sheeple are in the dark and don't understand what the machines do. Not to mention the political contributions & the additional employment it offers.
In fact, most screeners that stand by the machines all day don't realize that they are being radiated with spillover radiation. They are prohibited from wearing dosimeters. Just wait until the cancer cases start showing up & the taxpayers are left on the hook.
They say once you are past a certain point, you must be screened. Supposedly so that people could not make a "dry run" to observe procedures. I'm sure that people who are going to crash a plane while at the controls probably will go ahead and fly somewhere to avoid attention. Ya think???
Yes, and that's been tested in court.
This is off the TSA site:
If you refuse to be screened at any point during the screening process, the Security Officer will deny you entry beyond the screening area. You will not be able to fly.
That is only a half-truth. The rest of the truth is that once you start screening it must be completed. Is it a surprise that the agency isn't truthful? They won't even allow the scanners to be tested by an independent third party. "Trust us".
If you search, you should find the court case that reaches that conclusion.
With the chat-down interrogations, they're going far beyond the physical search into mind reading. Wouldn't an oppressive leaders like that ability...
A couple of other notes:
1) traveling internationally, I find that the security screeners are almost always more polite & treat passengers better, where in the US, TSA likes to scream and yell at people. Most international security folks believe in "requesting" that people do what's required, TSA on the other hand expects to "take command and control" and demand that people do things. The tension at US security checkpoints is far, far higher solely because of this reason.
2) At a certain foreign airport, the TSA has browbeaten the country into installing a body scanner for a few gates that are most often used for US flights. This is well past the regular checkpoint. So everyone is obligated to go through the scanner (no "opt outs"), but there is no accompanying x-ray machine. One could easily divest any "threatening" object into their bag and it will never be found. This is the worst sort of security theater: it is absolutely, totally ineffective, but is done a the behest of the TSA to make people "feel" safe.
. You're down to earth and reasonable. 
