In Missouri, which has some of the nation's harshest marijuana laws, there are two separate efforts underway to legalize marijuana for recreational use.

A bill filed last week by Rep. Chris Kelly (D-Columbia) would allow adults over age 21 to legally possess up to a pound of marijuana or hashish for personal use, and to grow up to eight cannabis plants at home. The bill, HB 1659, would also set up a system of licensed dispensaries, where every county could have one pot dispensary for every 2,500 people. The bill would also impose a 25 percent tax on sales of cannabis at the wholesale level.

Kelly told The Huffington Post that his experience as a circuit judge changed his position on legalization. "I saw a lot of marijuana cases," he said.

Currently in Missouri, you can spend up to a year in prison for possession of a single joint, even if it's your first offense. In 2011, about 20,000 people were busted for marijuana crimes in the state, and over 90 percent of those arrests were just for possession, according to the Marijuana Policy Project.

"The billions of dollars we've spent on the war on drugs has probably not stopped one person from smoking one joint. And it's ruined the lives of tens of thousands of people," Kelly said over the phone Wednesday. "Once you're convicted, you carry that around. You can't get into school. You can't get a job. And the question is, for what?"

Kelly stressed that the bill is still "very much a work in progress" and that there are some crucial changes he intends to make. For one, he will lower the amount of weed a person could legally possess. "One pound is probably too much," he conceded.

Kelly will also add a referendum clause to the bill, meaning that if lawmakers pass it, it will go to voters to decide. "It's such a fundamental change to the law, the people probably have to participate," Kelly explained, adding that he doesn't think lawmakers would approve it otherwise. "There's no way you could pass it straight through the legislature. But they [state legislators] might let the people decide," he said.

If the people get a chance to decide, there's reason to believe they would legalize the drug. A survey performed in September 2012 found a majority of Missouri residents supported taxing and regulating marijuana like alcohol.

Kelly's bill has not yet been sent to committee.

Missouri law allows for voter initiatives to make it on the ballot if they can get enough public support. Show-Me Cannabis is currently researching whether state voters would support such an amendment, the group's executive director, John Payne, told HuffPost.

"If public support is 60 percent or over, we are likely going to pursue a campaign this year," Payne said.