I hate to disagree with a fellow BMW owner, but...
The TSA is not going down the street dragooning citizens into being screened. Flying is voluntary, one of many ways to travel, and anyone who doesn't like airport screening has alternatives. The Fourth Amendment is not being ignored.
There is another issue here too, one that is rarely considered by those who object to screening because they believe their rights are being violated: What about the airlines' property rights? Do the airlines not have the right to set conditions under which people can board their flights? Do the airlines not have an interest in seeing that their airplanes are not damaged and their customers not harmed?
My first flight, 40 years ago, was on a DC-3, and I simply walked into the airport, went to the gate, and boarded it. No security to speak of, few restrictions on what I could carry, etc. Those days are gone, sadly, and with practitioners of the "religion of peace" constantly looking for new ways to kill infidels, this is the world we now live in.