The white-black gap in 4th grade reading scores is by far the largest in the most liberal jurisdiction, the District of Columbia

Steve Sailer on the NAEP 2009 reading scores:

Nationwide, it's 25 points, but in DC it's 60 points. The next biggest white-black gaps for 4th graders are in Minnesota (35 points) and Wisconsin (35). The smallest white-black gaps are in West Virginia (12 points -- dumb whites), New Hampshire and Vermont (few blacks), and Pentagon-run schools (need a 92 IQ to enlist).

Indeed, DC has by far the highest scoring white kids (15 points ahead of Massachusetts). It's black students are no longer the lowest scoring, being four points ahead of Wisconsin. (The worst scoring black 4th graders are in the socially liberal Old Northwest: Wisconsin, Michigan, and Minnesota. This is probably due in part to high welfare payments and easy eligibility requirements in the 1960s attracting the most feckless Southern blacks.)

Unfortunately, there aren't enough white 8th graders in DC public schools for the NAEP to come up with an adequate sample size of white 8th graders in DC.