"In the states that do have initiatives I expect efforts to get it on the ballot. The other half it will be much tougher. It's hard to get elected representatives to do this," Collins said.
Armantano is more optimistic about the spread of legalized pot. He compared the DOJ's announcement to the federal government's actions toward the end of alcohol prohibition in America a century ago, when states decided to stop following the federal ban on alcohol sales and the federal government said it would not step in and prosecute crimes.
"For first time we now have clear message from fed government saying they will not stand in way of states that wish to implement alternative regulatory schemes in lieu of federal prohibition," Armantano said.
He predicted that within the next one to three years, five or six other states may join Colorado and Washington in legalizing the drug, setting the stage for the rest of the country to follow.
Jim Pasco, executive director of the Fraternal Order of Police, the nation's largest police union, was disappointed with the Justice Department's decision, but said that he had already reached out to set up meetings to talk with leadership in the department and he was "open to discussion" about the benefits.
"I would tell you that certainly the overwhelming majority of law enforcement officers oppose legalization," he said, "but that is not to say that we're not willing to have a conversation about it. It is, from our perspective, a gateway drug and opinions to the contrary don't have the weight of fact behind them."
"We want to talk to (the DOJ) about their thought process and ours and where the disconnect is," he said. "From our perspective the only fault with the status quo is that we aren't making a bigger dent and we'd like to make a bigger one."