Having now read through the testimony, I don't see that as a bias. Asking a prospective officer of the US Justice Department whether they can apply the law in a color-blind fashion doesn't strike me as bias, but rather a very crucial question.
And while some may see it otherwise, I believe the wording of his question to prospective prosecutors is actually very important. Everyone, if asked if they can apply law in a color-blind fashion will, of course, say, "Yes." But ask it more specifically, that is, can you apply the law when the intimidation is against what we would normally consider the majority, but may be the minority in some areas, may well elicit a very different question.
Pollsters know this fact. Ask people currently if they would vote for a generic Democrat against a generic Republican, and the Republican likely wins in a landslide. Give specific names that people know and suddenly the question is no longer theoretical, but real, and the results are likely to be much different.
So, ask idealistic young lawyers looking to change the world, "Can you apply the American law to all, in spite of their race?" and you likely will get an answer in the affirmative. Ask, "Can you apply the law on voter intimidation to protect white voters against black intimidation?" and you are likely to get a very different answer, as Coates clearly did and which is what his political superiors were objecting to, since clearly their answer to the same question would have been, "No."
If I were in the position of the current DOJ appointed leaders, I would be very concerned that a future administration might view such blatant statements of prejudice in applying the law as reason for prosecution (or, perhaps, persecution). And giving a false answer to an investigating official, be it Congress, FBI, or whatever, can, as Scooter Libby can explain, be disastrous.