Gary Johnson, New Mexico's former governor and now the Libertarian party's nominee for president, said he stopped using marijuana recently because he wanted to be "knife sharp."

"I've always viewed the legalization of marijuana as making the world a better place," Johnson told CBSN in an interview Wednesday.

When prompted about why he stopped using marijuana, Johnson, who was once CEO of the publicly traded Cannabis Sativa, a marijuana products company, said it's because he wants to be "knife sharp."

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Johnson, who pushed for pot legalization in 1999 long before states began decriminalizing the substance on an ad hoc basis, said that medically, there was "not one documented death from marijuana" and that it can "directly compete" with legal prescription drugs.

On recreational use, the Libertarian candidate argued that "legalizing marijuana will lead to less overall substance abuse because people are going to find it a safer alternative than everything else out there, starting with alcohol."

Johnson also argued in an interview with C-SPAN's "Washington Journal" interview Tuesday that marijuana taxation could provide an "added revenue source" for state governments and that its legalization in certain parts of the country has led to more robust economies.

"Colorado is a vibrant place," Johnson told C-SPAN. "Does it have to do with marijuana? I think it has something to do with it. Colorado is at the top of the list when it comes to personal liberties and freedom."

A Fox News poll last month found Johnson attracted 10 percent support in a match-up against Trump and Democratic front-runner Hillary Clinton. William Weld, a former Republican governor of Massachusetts, is Johnson's running mate on the Libertarian ticket.