This illustrates the challenges facing both candidates in the next week and a half. Clinton needs to hold on to white men in both states, something she has not been able to do in recent primaries. She also needs to keep big margins among white women--those margins have been smaller in recent primaries. Obama needs to cut into Clinton's support among those two groups, particularly in Ohio. It will be interesting to watch whether we see any movement in support among these groups in the next week or so.
However, the other key for Obama is getting big turnout among African Americans in both states. Since that group votes so overwhelmingly for him (usually about 85%), he gets huge bang for the buck if he drives up turnout among African Americans. Clinton would similarly benefit from higher than normal turnout among Hispanics in Texas.