When people say that there are really “two Americas” — one for the affluent and one for the poor — cases like Hudson v. Michigan are an illustration of what they mean. Hudson, decided yesterday by the Supreme Court, struck down the rule that evidence must be supressed if officers executing a warrant fail to knock and announce themselves before entering the house they plan to search. Cops could already ask a judge for a “no-knock” warrant if they believed there were exigent circumstances to justify  barging right in. Now, not even that formality is necessary.

Now, police can adopt a policy of “Crash and Grab.” And we can be fairly certain that that’s exactly what they will do. Especially in drug cases, because the need to preserve evidence will always make it advantageous to catch suspects by surprise, even if it involves breaking the door down.

Justice Scalia, who wrote the majority opinion (this was a 5-4 case), argued that the implications of the decision for criminal suspects were minor. But although he is sometimes right about Fourth Amendment issues, he is wrong about this one. He is speaking from the perspective of wealthy America, for whom this decision will indeed be largely irrelevant. For poor people,Hudson is going to be an absolute disaster.