Watching Conor McGregor racing through the loading dock at Brooklyn’s Barclays Center on Thursday, throwing dollies at a bus like some crazy-eyed hooligan, I could only think of John McCain.

It was the US senator who years ago denounced the UFC as “human cockfighting”, affixing a label of lawlessness on mixed martial arts that pushed them into the corners of what was considered acceptable adult behavior. The UFC has worked for years to combat this image, with brain safety and doping mandates that helped attract a corporate buyer and led McCain to reconsider his opinion.

Conor McGregor charged with assault following UFC backstage melee in New York Read more

“The MMA cleaned up their act, they really did,” McCain told me in 2016. “When it first started they were able to do things that are now prohibited. I don’t have a problem with the MMA.”

Now the UFC’s biggest name, their star who burst into the mainstream, landing on magazine covers, luring many to a sport they’d never might have never considered, has been charged with assault and criminal mischief. One of these counts is a felony. And it does far more than any bloody brawl or failed doping test to destroy the credibility the UFC has built in recent years. The videos of the organization’s most visible fighter raging across concrete corridors, hurling garbage cans, project to the world an image that confirms McCain’s original impression.

What does it say about the UFC when the only fighter to hold titles in two of its divisions at once starts acting a common hoodlum?

Play Video 1:24 Conor McGregor attacks bus backstage at UFC event – video

Two years ago, back when he still came off as clever, McGregor once sat in a pre-fight press conference with Nate Diaz and said Diaz had “a bully mentality”. He then mocked Diaz’s mentors – some of whom are MMA royalty – as “bums.” As he said this, McGregor wore a fine plaid suit. He looked elegant. And even though he tussled with Diaz on stage, he still came off as regal, the fighter with an uncanny ability to describe exactly how he would win his fights. For this he became known as “Mystic Mac”.

But there was nothing mystical or magical about the man bellowing through Barclays with a posse of sycophants, scampering from security, flinging anything not bolted down at a bus filled with other fighters. When he threw the dolly through the bus window, he allegedly injured lightweight fighter Michael Chiesa and flyweight Ray Borg enough that both were pulled from Saturday’s UFC 233 card. McGregor came off as the very things he once decried: a bully and a bum.

Maybe, in a way, this was some kind of extravagant fight promotion. The real target of McGregor’s ire was supposedly Khabib Nurmagomedov, the rising lightweight star whose fight with Max Holloway on Saturday night was for the belt McGregor was stripped of for not fighting in the UFC since November 2016. McGregor was once a master of hype, building hysteria for his fights with profane tirades.

What happened Thursday was no masterful stroke of promotional genius. McGregor’s act has grown tiresome in recent months as his star has peaked and he almost seems to have developed a compulsion to be outrageous. He looked tacky and obnoxious in his pre-fight tour with Floyd Mayweather before their fight last year and in dragging his gang of hangers-on to charge a bus under an arena two days before a big fight night was stupid. There’s no honor in getting arrested for potentially damaging the careers of other fighters. McGregor, a man obsessed with money, should understand that. With Chiesa and Borg’s withdrawls and UFC president Dana White’s removal of Artem Lobov (who was with McGregor on Thursday), he may have cost the UFC three fights on Saturday’s card. When Holloway was declared medically unfit to fight on Friday morning, the UFC was left with a shell of an event.

“This is the last stunt on earth that we’d ever pull,” White told ESPN.“This is embarrassing for the sport and obviously for the UFC. This is the furthest thing from a stunt. This is bad.

Times have changed. This isn’t the old anything-goes UFC. The work White and others did to polish the organization’s image resulted in a $4bn sale to WME-IMG. The modern UFC is not the renegade UFC. They are a huge corporate entity desperate to appeal to the mainstream. What McGregor did on Thursday might draw a knowing smile from a fight fan who will shrug the whole thing off a part of “fighting”. But it doesn’t appeal to the broader world that puts people like McGregor and former female star Ronda Rousey on magazine covers and television commercials.

“It’s out of character for Conor McGregor and any of my fighters,” White said in his ESPN interview, looking shaken by what happened. “Listen, crazy things happen in sports. ... In the history of the UFC, this is definitely the worst thing that’s happened. This is not Conor McGregor. This is not the Conor McGregor that I know.”

UFC executives have been frustrated with McGregor ever since he knocked out José Aldo in 13 seconds back in UFC 194. The win propelled McGregor to new fame, making him almost bigger than the organization himself – something he exploited to become increasing more difficult to control. They put up with his behavior because, for a time, it made them money.

But this time McGregor crossed a line. White is right, the McGregor of recent months, the McGregor on Thursday, was nothing like the one who became the UFC’s greatest star. He has to make a choice now. Does he want to be a champion or a bully and a bum, throwing it all away to throw trashcans at buses?