Yeah, I know cities tend to vote liberal, but DC has always seemed extreme to me, even accounting for that. I mean, I don't have data for how big cities vote in general, but I thought it was something like 70% liberal. A solid majority and dissenters.
But DC voted 93% Democrat in 2008. 93! That's not a majority. That's a consensus.
It's on the high end, but I think around 80-90% Democratic for an urban core is fairly common. It's hard to get exact numbers because it depends on where lines are drawn. For example, Cook County (where Chicago is located) "only" voted 76% Obama, but it includes a number of suburban areas, and would be >80% if you pruned them.
Here are the next-most-Democratic cities I came across in some spot-checking, with NYC boroughs broken out b/c they're separate counties: 89% Bronx (NYC), 86% Manhattan (NYC), 84% San Francisco, 80% Brooklyn (NYC), 79% Boston, 79% Alameda County (East Bay), 77% Portland.
Silicon Valley is closer to the 70-ish you're thinking of, but it includes a number of quite suburban areas. Obama won 74% in San Mateo County, and 70% in San Jose County. LA County is about the same (70%), as is Fulton County (Atlanta).
Sorry, I guess we're a bit overly fussy out here. That one would be Los Angeles County. (Not that you couldn't call it LA County, just doesn't sound quite right. It's not uncommon to abbreviate the city to LA, but not so much the county.)
I don't think that's true of the past decade or so. While DC's outlying suburbs in Virginia and Maryland are more Republican than the urban core, they most certainly vote more Democratic than the average suburban county elsewhere in the U.S.
It's been as high as 71.1% Black (in 1970). The percentage has been decreasing as Blacks have moved to the suburbs and Hispanics have moved into the city.
I'm not. If you ever visit, it's pretty clear where each economic group lives. Practically anyone with money who works in DC lives in VA or MD. DC has the highest ghetto per capita in the world.
It's not just the "ghetto" that votes Democratic - those suburbs are a major factor in the leftward swing of Virginia and Maryland over the last decade.