The second reason that I don’t trust the neighbor method is that people just… aren’t good at knowing who a majority of their neighbors are voting for.
This seems like a point in favor of the neighbor method, not against it. You would want people to find “who are my neighbors voting for?” too difficult to readily answer and so mentally replace it with the simpler question “who am I voting for?” thus giving them a plausibly deniable way to admit to voting for Trump.
Any agent that makes decisions has an implicit decision theory, it just might not be a very good one. I don’t think anyone ever said advanced decision theory was required for AGI, only for robust alignment.