Because the supreme court is often hot garbage and basically gives handjobs to the police state.
They had to twist themselves in all kinds of knots in numerous cases to justify the things. Then they invented bullshit to make it sound like it wasnt a wholesale 4A violation (eg, like randomizing the cars selected etc)
Then they made up a faggot excuse that being arbitarily detained (by being forced to queue for this crap) wasnt a big deal so we're going to allow it" or similar BS
logic. Then they never bothered to define "What a big deal was" eg, like how long could you be forced to wait to go through the thing, etc.
Their failure on DUI law (WRT 4A violations) is almost as bad as Kelo vs New London or for that matter, Abramski. (A case where they could have easily defined straw purchase law to be less faggoty without nullifying the entire law).