Earlier quoted context omitted.
yes but you could say that of cars too (and courts have ruled mandatory DUI tests legal)
Just because courts have ruled something legal doesn't make it Constitutional. See: 100 mile border zones that are "exempt" from the 4th Amendment. Not to mention, just because something is legal doesn't make it right.
what SCOTUS says defines what is constitutional. you may disagree with their ruling but they are the meaningful authority.