Former Governor of Massachusetts Bill Weld says it makes a lot of sense for Republicans, like President Donald Trump, to support de-scheduling marijuana.

"I would think it's excellent politics for President Trump. He did say during the campaign in 2016, adult recreation, full adult legalization, is a states' rights issue — and that goes down very well with Republicans," Weld said on CNBC's "Fast Money."

"Including this former Republican," Weld added, chuckling.

The former Republican governor of Massachusetts-turned Libertarian has made his newfound feelings about marijuana well-known, since announcing last week he would join former House Speaker John Boehner on the board of medical marijuana company, Acreage Holdings.

"There's almost no logical argument against" de-scheduling marijuana, he said on Friday, adding that problems like banking would resolve themselves if marijuana's scheduling — or level of regulation — were reduced.

Furthermore, Weld not only thinks marijuana would fit well into Trump's political agenda, he thinks the president might be leaning toward loosening regulations already. To demonstrate, he referenced an upcoming hearing on de-scheduling marijuana, requested by the Trump administration, as well as Trump's recent comments to Senator Gardner of Colorado.

"President Trump talked with Cory Gardner, Republican Senator from Colorado...and said, 'No, no, I'm going to take care of the rub between the Feds and the states. If it's legal in Colorado, we'll make sure you don't get prosecuted for that,'" Weld said.

"That's the President of the United States talking, so that's pretty high cotton," he added.

As for full legalization, Weld didn't seem opposed, but he said he thinks it is "still years away for all 50 states."