First, good luck driving to Hawaii or Alaska. Second, while air travel isn't mentioned, the constitution, as I understand it, applies to everything the federal

First, good luck driving to Hawaii or Alaska. Second, while air travel isn't mentioned, the constitution, as I understand it, applies to everything the federal government might do, and since TSA is a federal agency, what it can and can't do is very much governed by the constitution. Random searches of people driving cars are unconstitutional, even if the constitution doesn't grant you the right to drive. After all, you could walk to (almost) anywhere in the US, right? If Wal-Mart decided to put up these scanners, it could very well be illegal, but it would never be unconstitutional.