Probably 0bama and Holder would like for it to come out right before election day, so as to rile up their base. If enough are rioting for a few days, they figure that the typical GOP voters will be too afraid to go to the polls. IMHO
They should release the info on election day morning, then the ferals everywhere in the country will be too busy looting and burning to be voting
Blacks are only 12% of the population, and a nearly unified voting block to begin with.
Pissing off the law-abiding vast majority of American voters is not a way to build a coalition.