'Pot just makes you dumb'

Smoking pot makes you dumb.

Host Joe Scarborough expressed this belief in a column published Monday on Politico''s website and on Wednesday's Morning Joe. Despite his awareness that most of his heroes used the drug, he said he never participated because he witnesses the negative effects of marijuana on some of his childhood friends.

"Smoking a joint on a Saturday night: I know a lot of really, really highly functioning, successful rich people that still do that," he said on the show. "[But] I have sat with a lot of kids that, when I was a kid, cried in rehab."

"I think with the medical evidence, it's not just a gateway drug," said Steve Rattner, MSNBC's economic analyst. He questioned which was worse: smoking cigarettes or pot on a Saturday night.

Colorado became the country’s first state to sell recreational marijuana legally beginning on the first day of the new year. Twenty states and Washington, DC currently have medical marijuana rules. But use of the drug is still considered a crime under federal law.

Related: Colorado starts 2014 on a 'high' note

A majority of Americans–58%–agreed with Coloradans about marijuana for the first time last October, according to a Gallup Poll. When the organization first asked the same question to the public in 1969, a mere 12% favored legalization.

Additionally, a new poll found that 55% of Americans believe pot should be legalized, according to a CNN/ORC International poll published earlier this week. Forty-four percent of the public said it should not be legalized.

"As a parent, I wish it was getting harder for them to get their hands on drugs," said Nicolle Wallace, former communications director for President George W. Bush.