All joking aside, the ruling had a lot to do with what is called "plain view" search. The molecules and atoms that the dog can smell are in 'plain view' to the dog. This ruling had to go this way or the chemical sniffers that the US Gov antiterrorist folks are implementing across the US would also be inadmissable in court against the bad dudes with large or small explosive devices and radiological weapons.
That's why the Conservative majority went this way. They are protecting our collective right of self defense against attackers.
If a dog alerts on your vehicle and it is searched, contraband MUST be found for any arrest to be made. Drug dust on money is insuffient as it does not represent a measurable amount for an arrest to be made.
I do agree that rights are historically lost when we need to become 'safer'... and this may represent such a loss.
No need for a constitutional amendment, let unelected judges do it. That way, nobody can be blamed.