The liquor lobby, the tobacco lobby, the jail lobby, the gun lobby,... but also the terrorist lobby.The hard part about making pot legal is fighting the Liquor Lobby. They know from studies where pot is legal that the consumption of alcohol lowers when legal. It's always about the money. Also a lower suicide rate where pot is legal.
Since Obama signed the 2012 NDAA bill, I got the feeling that the war on terror is the same type of fear selling business than the war on drugs.
Drug prohibition is the fuel of banditism and terrorism. The two wars are essentially the same war, the same criminal business.