Surprisingly, among Black voters, Coleman leads Franken 52-40 while Ciresi leads Coleman 51-43.
Of course, when your sample size is 628 and Blacks make up only 3% of registered voters in Minnesota, the sample probably consists of fewer than 20 voters. It's hard to draw meaningful conclusions from such limited data.
In the bigger picture, though, this is very good news for Franken and Ciresi. According to MyDD, Coleman's lead over Franken has collapsed from 22 points to 7. Coleman's lead over Ciresi has shrunk like Alice slipping under the door. Coleman led Ciresi by 23 in February and leads by 6 now.