In 2012, when Colorado voters passed Amendment 64, legalizing pot for recreational use was called “The Great Experiment.” Five years later, recreational pot is now legal in eight states plus the District of Columbia, while 21 other states now allow sales of marijuana for medical use. But anti-marijuana advocates – including U.S. Attorney General Jeff Sessions – are pushing back against more permissive state laws. Barry Petersen looks at how that “Great Experiment” is working out.