If you can't be IDed on a bus, then you can't be bag-searched getting on the subway, either. Both cases have a public conveyance, the right to travel, and no probable cause. Ironically, profiling could cause these to meet the probable cause requirement.
""If you can't be IDed on a bus, then you can't be bag-searched getting on the subway, either""
You can be both, depending on specifics of the situation.
If a captured terrorist claims an accomplice is readying to board the metro with an explosive device, the authorities are placed at all entrances and exits to check bags, this is not allowed? Under what premise? Are there bag checks for folks who tour the whitehouse? No backpacks allowed at 4th of july celebration on the Mall?
The list is endless. The point is there is no violation of rights because there is no requirement to tour the whitehouse, etc. Andrews AFB airshow is another example. Everything checked to get in. If I don't like it, I don't go. I certainly don't sue someone about it...