Ken Casey, frontman for the Boston-based Irish American rock band Dropkick Murphys, is going viral for his "friendly wager" with people who were wearing MAGA merchandise at the band's recent concert in Clearwater, Florida.

"Credit where credit is due these MAGA fellas upheld their end of the bargain after losing the bet," the band captioned the video they shared on social media on Monday, March 9.

"We miss the days where we all got along before this divisive, selfish con man came along.

"#trumpsucks."

In the video titled 'Dropkick Murphys vs. MAGA Wager,' Casey tells his audience: "The reason we speak out - we don't care if we lose fans because when history is said and done, we want it known that Dropkick Murphys stood with the people, we stood with the workers."

Casey asked the people in the crowd who were wearing the MAGA merchandise if they were up for a "friendly wager," and when they agreed, Casey acknowledged they were "good sports."

Casey asked if they support American workers and American businesses, which drew cheers of agreement from the crowd.

"So I don't know if you guys are aware because we don't go around f--kin' bragging about it, but Dropkick Murphys always sells proudly Made in America merchandise only," Casey said, again prompting cheers from the crowd.

"And here's the bet I'd like to make. If you lose the bet, we switch shirts. If you win the bet, I give you $100 and the [Dropkick Murphys] shirt."

A member of the Dropkick Murphys' crew then checked the tag on the MAGA shirt the concert-goer was wearing.

The MAGA fan's shirt, it turns out, was made in Nicaragua.

The man - who Casey again declared was a "good sport" - quickly took off and tossed his shirt on stage. In exchange, Casey threw him a Dropkick Murphys shirt.

Several angles and cuts of the interaction are circulating on social media.

In one version of the video, Casey tells the crowd: "...that's what makes America so actually great that you guys can speak your mind and I would never suggest the crowd f--kin' boo you or turn on you because this is America!

"It's kind of a free country still."

In this clip, Casey asks a man wearing a black MAGA hat - which Casey describes as "the Elon Musk true Nazi version" - to see where it was made.

The black MAGA cap had no tag, to which Casey said: "And you know what that means? It wasn't f--kin' made in America!"

At the end of the interaction, Casey again acknowledged that the MAGA fans were "good sports" before adding: "I will say, from the bottom of our hearts, we are the most anti-f--kin-MAGA band on Earth.

"But all opinions are welcome because it's still America!"

On social media, some fans asked why the MAGA fans were even at the concert as Dropkick Murphys have been vocally anti-Trump for many years.

Others told the band to stick to the music, again prompting fans to point out that Dropkick Murphys have always been unapologetically political.

Indeed, it's not the first time Casey railed against Trump and MAGA merch while on stage at a concert.

During a 2022 gig, Casey told the crowd: "... if you're out there buying those f--kin' hats that these swindlers are selling at that f--kin' fair - I'm sorry kids, I know there's kids here - then you're part of the problem.

"And I'll tell you why: because you're being duped by the greatest swindler in the history of the world.

"You're being duped by a bunch of grifters and billionaires who don't give a s--t about you or your family.

"They care about their f--kin' tax breaks and the money they can put in their pocket.

"If you consider yourself a patriot and you're spouting out that election-denying s--t, I will fight your a-- outside if you want to.

"Wake the f--k up.

"We're working-class people. These people are the f--king rich, the billionaires, and they don't give a s--t."