the police have more than enough tools for catching criminals without needing to violate the constitution.
Well, actually they don't.
-You have something for your own use in your own home, that you don't talk about publicly. Except it's illegal.
-You purchase a product from a willing seller, and you're both happy with the transaction. Except the product is illegal.
Not only are these two scenarios just illegal, but society has demanded that they need to be extremely aggressively enforced. There is simply no way for the police to do that without large scale and unambiguous violations of our rights. What needs to happen first is ending this ridiculous war on (some) drugs, which was the original justification for shredding the constitution (and also the vast majority of 'anti-terrorism' powers: they say they're to prevent terrorism, but are almost always used instead for domestic drug war cases).