I'm coming to terms with my prior post. Those who have completed CrimPro are almost certainly aware of a "special needs" exception to the warrant requirement for searches. That basically means where a search is necessary to preserve safety, the government may engage in such a search without a warrant. That's apparently how you can have the drunk-checkpoints and the TSA searches.
Of course, this brings up another question: If the TSA searches my bag for weapons or explosives or something and they find a brick of cocaine, could they still charge me with possession? In other words, is non-safety-related information from the search admissible when the exception to the warrant requirement is solely to preserve public safety? Must the TSA simply confiscate my cocaine and let me go because they can't use it for evidence? Does that mean that they can't charge me for explosives, should they find some, if the reason for the search is to protect safety, not investigate crime? What is the logical difference between using the explosives for evidence versus using the cocaine? Or may the government use any evidence discovered in a special needs search, and if so, doesn't this sort of abrogate the 4th Amendment in these situations? If that's true, and given the dog sniff cases, what is to stop the police from setting up a dog unit at the drunk driving checkpoint to see if those stopped have drugs?
Man, this class will be fun. I'm sure most if not all of these questions will be answered. Or at least answered to the extent case law allows.
