Terry Smith offers this post on Blackprof.com. A snippet:

When the authors of the two leading texts in the election law area systematically omitted citation to all but one or two African-American scholars in the area, the proper question for them was not whether they had a racial motive, but rather, how can anyone purport to be a true scholar if they overlook a relevant body of scholarship–in a textbook, no less? And the question for all minority scholars when faced with a glaring oversight (or slight) such as this is whether we demur or flinch.
When I saw that these texts had favored student notes and white authors with placements in secondary journals to the work of minority scholars, I advised a white mentor that I would pen a joint letter, signed by other minority scholars, to the authors regarding their egregious omissions. The mentor-whom I believe to possess good intentions, though that is never dispositive for me-counseled me not to write such a letter because it would impede my ability to move to a higher-ranked law school. Wrong person. Although I could not gain a consensus regarding the joint letter, I have made it my business to point out when publications and symposia-especially those that directly implicate minority interests-neglect the contributions of scholars of color.

As one of the authors of those casebooks, I’ll let others judge the fairness of these charges.