Statistical explanations and the 2nd Presidential Debate

After the 2nd presidential debate, I was watching the MSNBC discussion and Al Sharpton made the point that the area had a lot of African Americans but only one African American was there to ask questions. Earlier this campaign cycle Mitt Romney in one poll scored a 0 with African Americans. In a poll they found absolutely no African Americans who supported Romney. It's quite rare. But, also very relevant. The makeup of the audience of the town hall there is "undecided" voters, who are uncommitted and from the local area. That's a massive bias in the numbers. That demographic isn't the wishy-washy with support. Hence the appearance of white-washing.