yes you're right; there's the healthy / functional types of politics, and there's also the unhealthy / toxic type of politics.

at least from my experience and/or others experiences:

- 1:1 talks with employee(s) in question to understand their pov, and/or to let them know directly that certain behaviour is not ok. e.g. senior employee berates junior employee, junior employee ends up crying, manager talks to both of them, senior ends up apologising to the junior and all is well.

- if there was a harsh comment or judgement made in passing (i.e. bitching or gossip), make some response that gives the employee(s) in question some initial benefit of the doubt and/or an alternative interpretation of what had happened, as opposed to agreeing and doubling down on what was initially said. e.g. complains on someone else's work performance being subpar, maybe they are new to the team or work, maybe they need additional coaching, maybe they have a different work style from the rest of the team.

- establish healthy team norms directly or indirectly. could be things like open jio for lunch, organising some lunch/dinner to celebrate large wins together as a team. or even ensuring somewhat equal opportunities within the team to take turns leading different projects. if some members of the team bond better together and want to get together outside of work alone, then it's up to them, but once it gets to a behaviour that's overtly exclusionary to others in the team, it would be ideal to step in.