My understanding is that you can't legally have any sort of explicit quota or scoring system, but that you can sort-of factor in race, ethnicity, or gender to m

My understanding is that you can't legally have any sort of explicit quota or scoring system, but that you can sort-of factor in race, ethnicity, or gender to meet diversity goals. Is this correct? And isn't it kind of inconsistent? Whatever sort of decision-making process a recruiter goes through, one could imagine a mathematical formulation of it that matches up to some tolerance. Would such a formulation be illegal, since it must assign a weight to race at some point, even if the recruiter's vague sense of "I kind of want more diverse hires" is legal? In fact, doesn't disallowing any sort of numbers-based approach increase the likelihood of human bias creeping in, which is a lot of what diversity hiring is trying to correct for in the first place? Why should a practice only be illegal if you put explicit numbers around it?