Why Scott Gottlieb is calling on the federal government to regulate marijuana

With news that the recent rise in lung illnesses has been linked to tainted marijuana liquid, former FDA Commissioner Scott Gottlieb's asking the federal government to step in. In his most recent Wall Street Journal opinion piece, Dr. Gottlieb says it's time to challenge state pot laws which he says promotes risky use of the controversial drug. He joins "Squawk Box" to discuss his position.