In an appearance on Fox News "Sunday," Paul said he's working on a bill with Sen. Patrick Leahy, D-Vt., to institute mandatory minimums for possession of marijuana.
"The main thing I've said is not to legalize them but not to incarcerate people for extended periods of time," Paul said. "There are people in jail for 37, 50, 45 years for non-violent crimes. And that's a huge mistake. Or prisons are full of non-violent criminals."
Paul said he doesn't want to encourage people to smoke marijuana because he believes it takes away the incentive to work and do things "you should be doing."
"There are a lot of young people who [smoke marijuana] and then later on in their 20s, they grow up and get married and they quit doing things like this, I don't want to put them in jail and ruin their lives," he said.
"Look, the last two presidents could conceivably have been put in jail for their drug use, and I really think, you know, look what would have happened, it would have ruined their lives. They got lucky, but a lot of poor kids, particularly in the inner city, don't get lucky. They don't have good attorneys, and they go to jail for these things and I think it's a big mistake," he added.