Let me relate a personal story. I was traveling to see my family back in El Paso. I was driving my Jeep CJ5 without the top or even the doors allowing anyone to see nearly every inch of my vehicle without any effort. I was stopped at a checkpoint just west of Gila Bend. I was asked the usual questions about where I was going, where I was coming from, etc. I answered them politely as I always have. I was then asked to pull off to the side for a secondary inspection. They ran a drug dog around my vehicle which turned up nothing,and then they decided to frisk me. This has never happened to me before, but I complied only because I didn’t want to be detained any longer than I needed to be. I still had a long way to drive. They didn’t find anything and finally let me go. Would you at least consider this to be a random search that doesn’t pass the 4th amendment muster? I do.
Again, the checkpoints used to be a means of checking your immigration or citizen status. Now they are used as a dragnet to search anyone they see fit for any violation.