https://en.wikipedia.org/wiki/Among_the_Thugs
Worth a go if you haven't already.... The author joins up with "supporters" from various football teams and follows them on their travels. At one point he meets up with Nick Griffins at a NF disco.
Will need a strong stomach though...
"I was surprised by what I found; moreover, because I came away with a knowledge that I had not possessed before, I was also grateful, and surprised by that as well. I had not expected the violence to be so pleasurable....This is, if you like, the answer to the hundred-dollar question: why do young males riot every Saturday? They do it for the same reason that another generation drank too much, or smoked dope, or took hallucinogenic drugs, or behaved badly or rebelliously. Violence is their antisocial kick, their mind-altering experience, an adrenaline-induced euphoria that might be all the more powerful because it is generated by the body itself, with, I was convinced, many of the same addictive qualities that characterize synthetically-produced drugs."