By Dan Kervick
Imagine that the US Congress someday decides that as a matter of national security it is imperative for each American adult to be in possession of a smartphone. (Perhaps they believe that we might all need to receive an important text message from Homeland Security in the event of a major terrorist attack.) Suppose also that at the time of this decision there are 100 million American adults still without smartphones, and that the average smartphone costs $200.
According to the Supreme Court of the United States, here is a procedure Congress is permitted to follow: