A left-leaning CNN contributor on Monday said that Americans who voted solely based on who let them "roll up a blunt" were foolish and shouldn't bother voting at all.

CNN's Carol Costello asked contributor LZ Granderson to respond to any of the Colorado voters who might be less likely to back President Barack Obama because he does not support marijuana legalization.

"Well, they're idiots," Granderson explained. "If you're voting for a president, any president, on one single issue -- especially one issue that is so peripheral such as marijuana usage -- you're a idiot. I don't want to mince any words here. We have way too many more important things to talk about as Mitt Romney said earlier, as the president has said earlier."

"So if you're basing your vote on who's going to be president about whether or not they let you roll up a blunt then you're just an idiot and I hope you don't have the right to vote anyway."

Conservative CNN contributor Will Cain suggested that legalizing marijuana could actually help to win the drug war, but he agreed that it was not an important issue for 2012.

"This will not be part of any presidential debate, nor any debate on the national stage," Cain predicted. "I believe it's 60 percent of the Mexican drug cartels are fed by the profits of marijuana. And I think there is a very logical argument to make about cutting the profits out. Any business, you cut 60 percent of the profits out of it, you're going to hurt them."

"The drug trade is more than just about morality," he added. "And there is a great debate on the morality of freedom versus vice. It's also about economics and crime, and what elicit drug use and drug sale, more specifically, does to the crime in the United States."

Last month, marijuana advocate Ellen Rosenblum overwhelmingly won the Democratic primary in the race to be Oregon's attorney general. And in Texas, pro-pot candidate Beto O’Rourke ousted incumbent U.S. Rep. Silvestre Reyes in the Texas Democratic primary.

A Gallup survey last October found that a record-high 50 percent of Americans favored legalizing marijuana.

Watch this video from CNN's Newsroom via Mediaite, broadcast June 4, 2012.