Moderators/leads in my neighbourhood frequently display open political bias in their subjective enforcement of the guidelines, quickly removing comments or ads that are posted by conservative members of the community, while leaving up entire threads discussing national politics from a left/liberal angle.
It appears they are happy to stretch the guidelines to their absolute limit in order to silence people they disagree with, while allowing undeniable breaches of the guidelines by those they politically align with.
The result is an echo chamber that is very unwelcoming for some sections of the community, and moreover there is no transparency whatsoever in how the moderators/leads make their decisions.