No job is interesting enough that I would tolerate targeting and succeeding in firing a productive employee for internal politics. Doubly so if that behavior is coming from a department nominally in a support role. That's a dog to be put down.
Maybe, but it's that type thinking that permits the behavior in the first place. People built the workplace and people decide what is acceptable.
Deciding to leave doesn't mean put in your notice. It means look elsewhere. Leaving a job without another secured is always precarious absent a nest egg.