> The idea of “outside agitators” coming in and having the power to change your community is a specious, pernicious myth.
Pessimistically, one could view the missions of HFH and and many HUD programs (esp. FHA) as exactly that. Every house built, bought, or renovated can affect change, and external assistance can tilt the changes. Ditto big developers coming in to "revitalize" urban areas.
However, while I would agree that local government is still generally pretty answerable to local voters, state and federal grants and other "external" sources of money can and do alter their priorities. Changing demographics, esp. simple population growth, can attenuate or amplify various voting blocs over time. Most change happens very slowly at first, but then suddenly accelerates.
No matter your politics, I think there are good examples of this. Whether it be poorer neighborhoods that suddenly get gentrified after decades of stability, pricing out families who've lived there for generations, or richer neighborhoods that suddenly get a low-cost complex built nearby to qualify for a grant or comply with a DOJ "consent agreement", the character of a neighborhood _can_ change quickly even if it generally _doesn't_. In these situations, the most that participating in local government will get you is advance warning, which is a lot less useful for the poorer example than the richer one.