I’ve seen several posts of people asking for advice on situations like this with so many answers suggesting OP to fight back, document and contact the union, but this seems too much work for an unconvincing result, because there is no way a manager is going to fire an employee or a clique for a “he claims she claims” situation.
Manager, employer, even the union, will listen to you, play theatrics and change nothing hoping you forget.
Walking away, while making you feel like a loser, seems to be the sane choice long term. Cliques are gonna clique.
Maybe you can think of a better way?
I guess you just need to document and escalate anything objectively wrong that they do. If it’s a one party consent state maybe you can record it, but I never experimented with that.
If HR can’t help you with any legitimate problems that a clique is causing, you’re probably right about the best option just being walking away. There’s nothing inherently wrong with cliques if it just refers to a group of friends.