Like GWB he is the decider and not really the person that is going to make the most informed choice according to Marijuana Politics who write

“Ironically and tragically, of over 200 million adult Americans, Iowa Senator Chuck Grassley is perhaps the least qualified all to be “the decider” concerning federal marijuana regulation. His drug war zealotry and cannabigotry stretch for decades. He has always supported the worst excesses of the war on drugs, including mandatory minimums, civil forfeiture, and harm maximization to cannabis users and their families. He has always fought any loosening of federal marijuana laws. And yet Chuck Grassley is the person who lets live or die the CARERs Act and with it marijuana rescheduling. It looks like he intends to let it die. Back when the bill was introduced”

Read their full report here
http://marijuanapolitics.com/chuck-grassley-killing-cannabis-rescheduling-carers-act/