CONOR MCGREGOR, also known as “The Notorious” and “The Dublinator”, is a mixed martial arts star and a big draw for the Ultimate Fighting Championship (UFC), the largest mixed martial arts promoter. A recent McGregor fight in Las Vegas fight drew 16,000 fans with a $7.2m live gate and 1m pay-per-view buys. The sport has come a long way from its early days when eye-gouging was permitted. Once described by John McCain as “human-cockfighting”, it is now mainstream and immensely popular. Millions of Americas happily pay $59.99 a go to watch top fights on pay-per-view television. In 2013, one of the owners of the UFC bragged to your correspondent that it was the world’s most valuable sporting franchise.

Mr McGregor reportedly earned $500,000 (not including bonuses or sponsorships) for a recent bout. But most UFC fighters make decidedly less. The median pay per fight is $24,500, and most pugilists get in the ring only a couple of times a year. Some fighters think the muscle of a union might help them get better pay and more say. Earlier this month, the Teamsters, along with a local culinary union, announced that they intended to help fighters organise.

The Teamsters were once a powerful labour force and infamously corrupt. This is no longer the case. In January the federal government said it would soon end 25 years of strict oversight of the Teamsters to stamp out corruption. At its peak, it had 2m members. Today it has 1.4m. The heart of the union was made up of lorry drivers, but in the early 1980s the trucking industry was deregulated. New companies were formed which preferred to work with non-union drivers, whose compensation was typically 26% less than union drivers. Before deregulation, the Teamsters had more than 400,000 truckers among its ranks. Today it has only 100,000. More than 250,000 members work at UPS, the courier company. It is the largest single employer of the union’s members.

Deregulation also caused the Teamsters to diversify, says Lee Adler of Cornell University. It has 80,000 airline workers, including flight attendants and pilots. It has bakers, cheesemakers, yogurt processors and vegetable workers. Its members include warehouse staff, railway engineers, secretaries and printers. The union also has 273,000 public servants, including police officers, sheriffs, school bus drivers and public defenders. In St Louis many brewers are Teamsters. Pennsylvania has some Teamster zookeepers. They ought to have plenty to talk about with the MMA fighters, who also work in cages.