When Kamala Harris picked up the phone and asked Tim Walz to be her running mate on Tuesday morning, Minnesota’s governor was sitting on a wicker chair in his St. Paul home wearing khakis and his customary camouflage hat.

“I would be honored, Madam Vice President,” replied Walz, a former high school football coach who hunts and fishes in his free time.

Soon, his Midwestern dad vibe was fueling social media memes comparing him to pop music star Chappell Roan, who has a “Midwest Princess” camo hat in her official merch line-up.

Riffing off the memes, the Harris campaign designed and produced a prototype within hours. By that evening in Philadelphia, Walz had the soon-to-be-viral hat in hand and tweeted a photo wearing it. 

The $40 Harris Walz hat – union-made by New Jersey-based manufacturer Unionwear – was an instant hit. 

The initial run of 3,000 hats sold out in less than 30 minutes, and the campaign has rung up more than $1 million in hat sales since the merch dropped Tuesday. Thousands more hats are on back-order until October. Sales of the hats benefit the Harris Victory Fund.

“Is this real,” Roan wrote on X over side-by-side images of her “Midwest Princess” hat next to the new Harris-Walz camo hat.

Mitch Cahn, Unionwear’s CEO, said he has sold about 100,000 Kamala hats for the campaign, the Democratic party, the Democratic convention and other merchandisers since Harris launched her campaign on July 21. 

About a quarter of those, according to Cahn, are the camo hats. 

Cahn said he expected a bump in sales after Biden dropped out of the race last month. But getting “absolutely crushed with business” was a surprise. 

“We are going to have to add a second shift and work weekends at least for the next two months with the demand that we anticipate,” he told USA TODAY. 

Campaigns often sell branded camo hats to appeal to red-state voters. These days, Carhartt-inspired camo has urban crossover appeal, as in vogue in New York cafes as it is on deer hunts in Minnesota. But can this upstart headpiece topple the undisputed king of campaign merch Donald Trump?

Campaign merch can generate "significant dollars," said Bruce Newman, founding editor-in-chief of the Journal of Political Marketing and a professor of marketing at DePaul University.

"It’s definitely not at the top of the pyramid, but it pays some of the bills," Newman said. "It’s also a marketing tool. You’re telling the world who you are and what you’ll do for them."

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Trump is in a class of his own when it comes to capitalizing on campaign merch, from golden sneakers to perfume. His iconic red MAGA hat is the stuff of merch legend.

Trump’s son-in-law Jared Kushner wrote in his memoir that the “Make America Great Again” hat brought in up to $80,000 a day during the 2016 presidential run, covering most of the campaign’s overhead costs.

"Trump wore the hat on his visit to the southern border, and it became the hottest thing on the internet," Kushner wrote in “Breaking History.”

No one has mastered the meme-to-merch pipeline quite like the MAGA universe, which milks political highlights to market T-shirts and trinkets. 

Even Trump’s scowl in his booking photo made its way onto mugs and NFTs in his campaign store. After he was taken into custody, the campaign sold bumper stickers and beverage coolers with the tagline: “NEVER SURRENDER!” Trump also sold pieces of the blue suit and red tie he wore in the mugshot. 

Trump campaign spokesperson Steven Cheung said the former president raised more than $4 million the day after he was booked at an Atlanta jail, at the time the highest-grossing day of the campaign.

The MAGA merchandise cottage industry roared into overdrive after Trump survived the assassination attempt at a campaign rally in Butler, Pennsylvania, hawking products featuring the bloodied but defiant former president clenching his fist. 

From T-shirts emblazoned with the rallying cry “Fight! Fight! Fight!” to "You Missed" shot glasses, the merch was a hot seller online and at the Republican National Convention in Milwaukee.

Will the camo hat be more than a folksy flash in the pan?

Unionwear hasn’t produced merch for the Trump campaign in the last two election cycles, but Cahn said the initial Kamala-Walz hat demand exceeds the initial demand for the MAGA hats his company made in 2016. 

It's not clear exactly how many MAGA hat sales are sold today. The Trump campaign did not immediately return a request for comment, and Cahn estimates that "most" MAGA hats are not sold by the campaign but by online and street vendors.

“Kamala has just completely taken everybody by surprise on this,” Cahn said. “We've seen so many units sold in such a short period of time. And as the merchandise gets out there, as more people see it, I think it's really going to take on a life of its own.”