Do blacks perceive more discrimination in high-black or low-black regions?

I don't know if anyone has put forward the hypothesis in some formal way, but I have run across the idea that while mistreatment by whites is common among blacks generally, it's REALLY bad in areas with few blacks. The reasoning seems to be that whites are very racist everywhere, but concentrations of blacks are able to push back and suppress the discrimination to some extent. By contrast, isolated blacks are more powerless and consequently have it really bad.

The General Social Survey (GSS) asked blacks, "How much discrimination is there that hurts the chances of blacks to get good-paying jobs?" Since there were only 152 respondents, I took the nine regions used by GSS and collapsed them into two: one high-black and one low-black category.
I also divided up the country into North vs. South under the assumption that the South is more racist.

Answers ranged from "a lot of discrimination" (4) to "none at all" (1) so higher numbers indicate greater perceived discrimination. Here are the means:

Mean perceived job discrimination

North High Black  3.56
North Low Black   3.38
South  3.29

The region with the greatest perceived discrimination is made up of parts in the north that have the most blacks. Contrary to the stereotype, there is no evidence here that the South is more racist--it scores the lowest. In the middle are low-black areas in the north. When I say north, I mean the mountain states and the west coast as well as the north proper. (You don't see a low-black southern region because there is no such place in GSS data.)

So GSS data contradict the view that black communities that are small, isolated, and surrounded by many whites have it really bad. Blacks think they have it better when their numbers are small.

My guess would be that perceived discrimination is affected a great deal by exaggeration, a phenomenon that gets magnified among large concentrations of blacks.

UPDATE: This hypothesis of large numbers magnifying the perception of discrimination doesn't work for the South which has many blacks but scores the lowest on discrimination. A reader suggested that progressives encourage blacks to see mistreatment, but some low-black areas contain many liberals: the West Coast, New England, Minnesota. I wonder if the perception of bias depends on how one is treated when applying for a job. Southerners and perhaps many people in low-black areas might have a softer touch than employers in places like Chicago or Detroit. Discrimination is typically an ambiguous thing. People are not going to admit that they're not hiring you because they don't like blacks, so people have to rely on cues. A brusque manner could be interpreted as bias.