The court previously has said that police may use drug-sniffing dogs at will during routine traffic stops and may search cars without a warrant, based on their own determination of probable cause. Now that it has said a dog's alert by itself suffices for probable cause, a cop with a dog has the practical power to search the car of anyone who strikes him as suspicious.
There's a great scene in the movie "The Right Stuff" where the original Mercury astronauts are checking out the capsule for their first trips to space. They're horrified to discover that the German scientists in charge of the program see the astronauts as nothing more than living props.
Prediction: Gridlock for the Next Two Years, but that’s Better than the Alternative | Daniel J. Mitchell