I've recently been examining the demographics of the states which have already voted, looking for any interesting patterns. I was not surprised to discover that Barack Obama has not lost a single state where over 18% of the population is African American. Given his strong support among African Americans, it would be nearly impossible for him to lose a contest where they make up a significant percent of the electorate.
What I did find interesting is that Obama has not lost a single state where 1% or less of the population is African American. Surprisingly, he has won Maine, Vermont, Idaho, Wyoming, North Dakota, and Utah; all have populations which are 1% or less African American. Although, Barack Obama did lose New Hampshire, where slightly more than 1% of the population is African American.
A large African-American community or near lack of one are both good indicators of where Obama is most competitive. If the patterns continue, Obama should be expected to not only do well in North Carolina, which is 21.7% African-American, but also be strong in nearly all-white Montana and North Dakota.
*all numbers from US Census Bureau