I've seen recent demands that Sunnyvale, a city of 140 thousand people, begin electing its city council by districts. (Currently the 7 members are elected for separate seats but all at large.) This is because, although the city - in the heart of Silicon Valley, the highest concentration of Asian population in the continental US - has an Asian population of 40.9%, there have rarely been any Asians on the council: maybe 2 or 3 in its history. There's none now, though there's one running for one of the three seats up next month.
The idea is that districts will enable concentrations of ethnicities to have a stronger voice than they do city-wide. But it seems to me that this will really only work if those ethnicities are geographically concentrated. But the Asians here are not.
Using the Census's American Fact Finder for the 2010 census for the city and its constituent zip codes, I divided the city into three zones of very roughly equal population:
1) north of Central Expressway, 94085 & 94089 (40,492: 28.9%)
2) between Central and El Camino, 94086 (45,697: 32.6%)
3) south of El Camino, 94087 (54,293: 38.8%)
The Asian percentages of the population are:
1) 36.6%; 2) 42.0%; 3) 43.1%
That's just not a very high differential. The only way district elections would facilitate the election of Asians is if there happens to be a district with a strong Asian candidate but without strong non-Asian candidates.
Where it could make a difference is with Hispanics, but not that much as the Hispanic population is only 18.9%. But the differential is strong:
1) 29.9%; 2) 21.3%; 3) 9.0%
(Black population in the city is only 2.0%, and there isn't a strong differential. There is one Black candidate in this year's Council elections.)
I think it would be far more effective to recruit more strong Asian candidates to run for Council than it would be to create districts.