American Future Fund is behind the online ad campaign "More Weed, Less War" which encourages young people in North Carolina to cast their vote for Libertarian U.S. Senate candidate Sean Haugh, who supports marijuana legalization. Editor's note: An earlier description of this video identified American Future Fund as a group supported by the Koch-backed donor network. The network says it no longer funds AFF. (Support Haugh For US Senate via YouTube)

This post was updated at 11 a.m. Friday.

Sean Haugh, the Libertarian candidate for Senate in North Carolina, is getting a big lift in the waning days of the election from an unlikely group praising his support for marijuana legalization and his opposition to U.S. military action abroad.

The “More Weed, Less War” online ad campaign features beaming young men and women who tout Haugh as “sharing our progressive values,” chant “Get Haugh, get high!” and dismiss Democratic incumbent Sen. Kay Hagan as “out of touch.”

The outfit behind the campaign does not have a history of advocating for marijuana legalization.

American Future Fund, a tax-exempt organization based in West Des Moines, has been frequently used as a pass-through for political money on the right. In the 2012 campaign, it was a major player in a network of politically active nonprofits supported by the billionaire industrialists Charles and David Koch and other conservative donors.

But James Davis, a spokesman for Freedom Partners, the main financial arm of the Koch-backed network, said it no longer funds the Iowa group and has nothing to do with its pro-Haugh campaign.

“Freedom Partners has not given American Future Fund any grants in the last two years and has no involvement with their current campaign in North Carolina," Davis said in a statement.

"Our focus continues to be on holding Sen. Kay Hagan accountable for her failure to fight for North Carolina’s veterans, how her family profited off of her vote for the stimulus and her rubber-stamp support for President Obama’s failed policies," he added in a statement, noting that the group's super PAC is currently running $1.1 million in ads in North Carolina backing Republican challenger Thom Tillis.

Nick Ryan, AFF’s founder, declined to say who was supporting the campaign. “As a practice, we don't comment on who does or does not contribute to our organization,” he wrote in an email.

He added that the goal of the pro-Haugh campaign “is straightforward — share information with voters about where Sean Haugh stands on a variety of issues.”

Ryan said the campaign is now generating so much buzz that AFF plans to expand its initial $225,000 buy.

“The response has been incredible online,” he wrote. “We are going to re-double our efforts and expand the program next week.”

Groups affiliated with the Koch donor network have made major investments in North Carolina. The advocacy group Americans for Prosperity spent millions pounding Hagan over her support for Obamacare early in the year, and Freedom Partners Action Fund has swooped in with new ads attacking her in the final weeks.

Benjamin Ray, a spokesman for the coordinated Democratic campaign in North Carolina, called the AFF ads "a last-ditch effort" by the Koch-backed network to erode Hagan's backing. Davis vigorously disputed the notion that the network was involved.

Whether the new spots will have an impact on voters amid the $100 million worth of ads that are expected to flood the state by Election Day is uncertain.

But the spending dwarfs the meager resources that Haugh, who works as a pizza deliveryman, has put into the race. The Libertarian candidate has conducted most of his campaign from his campaign manager's basement, recording YouTube videos.

“While I appreciate the support, I now have a whole new reason to despise Koch brothers & their dark money,” he wrote in a Twitter message.

In an email, Haugh wrote the ads “came as a complete surprise to me.”

“The source makes the intent obvious,” he said. “I've never spoken with AFF. I'm happy when anyone promotes my message accurately and tells anyone why they should vote Libertarian.”

He may have no connection to the current campaign, but Haugh does have a connection to the Kochs -- even if it is more than three decades old.

His first campaign job was gathering signatures to get the 1980 Libertarian presidential ticket on state ballots nationwide. The party’s vice-presidential nominee that year was one David H. Koch, the younger of the now-famous Koch brothers. Haugh said he found him “a sweet fellow.”

The new AFF campaign targets college-age Hagan supporters with images of a polar bear nuzzling with her cub and large marijuana leaves.

“Stop! Don’t even think about voting for Kay Hagan,” says a young woman in a spot. “She doesn’t share our values. You want legalization of marijuana? She’s against it.”

The ad then features a photo of the North Carolina senator with the words “Out of Touch” plastered over her face.

“If you want war, vote for Hagan,” the woman says in another. “If you want peace, vote for Haugh.”

Karen Tumulty contributed to this report