The Purple House, with the rest of the Potrero Hill neighborhood, is in San Francisco’s District 10. (The city is split into Districts for the purposes of electing Supervisors, one per.)
Many of the lists on the Resources page occasionally discuss politics, since as we know, all politics is local.
D10 Candidate Watch blog
Bayview Footprints “A Network of Community-Building Groups” focusing on the Bayview area