While visiting in Denver, Colorado this week, Rand Paul made history as the first major candidate to fundraise with the marijuana industry. But while Paul has been supportive of medical marijuana and decriminalization efforts, he tends to shy away from calling for all-out legalization nationwide, preferring to emphasize it as a states' rights issue.

Denver's 9NEWS pressed him on the point, asking if he supports legalization nationwide.

"I've spent most of my time talking about decriminalization," Paul replied. "I think putting someone in jail for 55 years for marijuana is ridiculous."

"You said you're for states' rights," the reporter continued. "Do you support, if you were President Paul, do you support allowing Colorado to go forward with what it has, or would you use federal powers against the [retail marijuana] system that we have?"

"Yeah, I wouldn't interfere from the federal level,” Paul said.

Watch below, via 9NEWS: