In the aftermath of John McCain’s death on Saturday from brain cancer, many have looked back at his long career and many milestones as a Republican lawmaker. One of the more overlooked aspects of McCain’s multiple terms as a senator was the time when he was mixed martial arts’ biggest detractor, calling the early Ultimate Fighting Championship events “human cockfighting” and tirelessly working to get the UFC banned well before MMA truly exploded in popularity.

During the first few years of the UFC, the sport was virtually unrecognizable in comparison to what it eventually became in the 21st century. As Slate recalled in 1999, early events were designed to prove the supremacy of one martial art over the other in eight- or 16-man tournaments. These often included fights with significant size mismatches, such as the UFC 3 match where 200-pound Kenpo karate specialist Keith Hackney dominated 600-plus-pound sumo wrestler Emmanuel Yarborough in a shade under two minutes.

Aside from established disciplines like karate, wrestling, and Brazilian jiu-jitsu, other competitors represented obscure or “exotic” forms of fighting, with UFC 4 entrant Joe Son’s “Joe Son Do” one of the more memorable examples, according to the Daily Beast. Fighters such as the “ill-tempered” Tank Abbott, who weighed about 275 pounds and sported a portly physique, were among UFC’s first few household names.

Through it all, John McCain was a thorn in the early UFC’s side, as he first launched his campaign to ban the fledgling company and the sport it promoted in 1996 after he was “horrified” by a tape of an early UFC event. According to Slate, the Arizona senator, who was a lifelong boxing fan and former Navy boxer, found the UFC’s brand of combat sport “barbaric,” saying that it was more “human cockfighting” than an actual sport.

With McCain sending letters to all 50 state governors and asking them not to entertain the UFC when it came to town, the promotion had to hold many of its early events in areas that were outside the jurisdiction of state athletic commissions, Boxing Insider recalled.

As the years passed, UFC officials worked toward regulating the sport and appeasing McCain and other notable detractors, eliminating the tournament system and establishing new sets of rules as MMA in itself continued to evolve.

By 2014, the sport had seemed to “grow” on McCain, according to Fox News, as he even went as far as purchasing UFC 172, where then-light heavyweight champion Jon Jones successfully defended his title against Glover Teixeira. At that point, he still wasn’t a “huge UFC fan,” but as Fox News wrote, his critical comments had become positive since the time he tried to get the organization’s events banned.

“I have to give him credit,” UFC’s then-CEO, Lorenzo Fertitta, told Fox News.

“Without him doing what he did back in the ’90s to force regulation, this sport would be dead. It wouldn’t exist. Honestly, for all the negatives he caused, he actually allowed the sport to foster and grow.”

Fertitta further stressed that John McCain’s criticism of the early UFC was valid, and was ultimately vital in MMA’s growth, as it evolved from its more violent, niche beginnings to a popular combat sport with mainstream appeal.

“He wasn’t saying in the past that he was necessarily against [mixed] martial arts, he was saying, ‘This needs to be regulated. It just can’t be a free-for-all. There had to be some structure to it. Once the states then embraced it, he was comfortable and he’s been a supporter since then.”

Similarly, UFC president Dana White told Sports Illustrated in 2008 that John McCain was the “guy who started the UFC,” as he wasn’t necessarily telling its old owners that mixed martial arts, in general, should be banned, but rather saying that it has to be sanctioned by a state athletic commission, according to MMA Fighting. The publication also quoted comments McCain made in 2007, where he said that White and other UFC officials who took over from the old regime “cleaned up the sport” to a point where he no longer feels it’s akin to “human cockfighting.”