UPDATE: I emailed Caplan about Schleicher’s theory. Caplan says his explanation is better.
Via Volokh, I came across David Schleicher’s Why is There No Partisan Competition in City Council Elections? The Role of Election Law. As a promoter of decentralization to roughly the city-state level, I had been interested in this issue and attributed it to the great salience of identification with national parties (one of which small districts will tend to overwhelmingly support with) and some unpleasantness of cognitive dissonance in voting for a party you’d normally hate, whereas if one country were split into smaller ones, new competitive parties would form around different median voters. Schleicher blames uncompetitive city council on Progressive Era “unitary party rules”. His paper brings up the competitive nature of mayoral elections in big cities, which I had underestimated (I guess I dismissed Giuliani as a fluke) perhaps because I live near Chicago. Oddly enough, Bryan Caplan recently pondered how the People’s Action Party in Singapore has so long held unquestioned monopoly of power (something Mencius Moldbug considers exemplary) and reflected that it’s just like San Francisco, and peculiar only due to its small size. As Singapore is not part of any larger state, the rules Schleicher focuses on shouldn’t be an issue. On the other hand, Japan has had basically one-party rule for a long time as well and is not a city-state. Elsewhere at EconLog, Arnold Kling grouses about his county of Maryland, which he compares to communist Eastern Europe in its prolonged one-party dominance. He blames that on those hypocritical liberals being able to accuse the right of hypocrisy while their powerless opponents can’t hit back.

I’ve never voted (for any election/referendum) or even paid much attention to local politics. I suppose my vote would be more likely to make a difference at the local level, but I still can’t be bothered.