Just finished the book, Blow's argument is solid. Black power brokers in the north/west have to compete with their "POC" counterparts and Blacks don't have enough demographically to consistently influence city and statewide outcomes.
For example,the asian communities role in the SHSAT and anti- affirmative action movements show that they now have the influence to sway policy that potentially undermines Black interest.
And so, given that the demographics will likely not change for the better, Blow's arguments are convincing.