Soccer in the UK and Europe has a huge issue with racism, so it's irrelevant for any club to claim they are "more racist" than the other. As a non-European, who has been immersed in the European cultures, it seems very cringe when a certain team always pointing fingers at the other team's fans or being "racist". It's a well documented fact that soccer is followed by people from lower socio-economic backgrounds in the UK, so these things such as racism, homophobia, xenophobia, etc are part and parcel of the sport.
As for the events today, I hope the fans get punished.