Anti-Foreign Bias Strikes Again

How does this show bias of an anti-sort? Anecdotally, most people I've ever talked about it with (including black people) overestimate the percentage of Americans who are black. Are black people anti-black? I think it has more to do with poor understanding of statistics and what we are more likely to notice than anything else.

Also, what happens when you switch the question around? What percentage of the population do people think is native-born? I bet we tend to overestimate that number too.

Portugal explanation: Brazilian and African (Angola, Mozambique, Cape Verde) Portuguese-speaking immigrants.

Maestro,

However, if you read the linked page, you'll see that overestimation by a person is correlated with greater opposition. So there is something there.

I am curious where the numbers for "actual" percentage come from. Specifically, I wonder how illegal immigrants are counted. If the "actual" really means "legal", then the perception might be the more accurate number, and the anti-foreign bias might be an anti-illegal immigrant bias.