The fourth amendment is a de jure ban, and shouldn't a de jure ban be a de facto ban for law enforcement? The lawful way to make it de facto is to make it de jure first by repealing that pesky amendment.
The US government flouts the constitution constantly, for example the UN charter which according to the constitution, treaties are part of the supreme law of the land. It's a security state designed to squelch popular resistance to a global imperial project (that is currently floundering).
Yes, but treaties are still subjugate to the Constitution. Congress isn't authorized to violate the constitution, amd thetefore isn't authorized to enter into treaties which would do so.