Conservatives (and the threat of conservative backlash) can nonetheless meaningfully influence the shape of institutional policies that hinder the stated goals of the organization, municipal government or otherwise. It's not at "tyranny of the minority" levels in many cases but that doesn't mean they're completely shut out.
Intention matters little when it comes to outcomes -- this is the credo of the consequentialist. It's about the material facts as regards what specific elements of specific policies promote or discourage this or that outcome. Deft policymakers can find sneaky leverage points that are only obvious in retrospect as having been a significant influence on the outcome vis a vis the stated goals of the policy in the first place, and it would be naive to assume that large political organizations (parties, PACs, etc.) on both sides don't develop and hire talent to provide exactly this kind of service. It's a battle of shadow consultancies just as much as it is a battle between ideologically-motivated parties, even though you are only exposed to the dramas of the latter in news media.
They're pushed out, either through police violence or a complete lack of viable social support systems. There's many ways to discourage folks from sticking around through ad hoc policies without putting it explicitly into law, or else to simply not mandate the kind of support that other cities have.