The interviewees in my study who were most angry about affirmative action were those who had relatively fewer marketable skills — and were therefore most dependent on getting an inside edge for the best jobs. Whites who felt entitled to these positions believed that affirmative action was unfair because it blocked their own privileged access.
This is almost certainly backwards. I believe her when she finds a negative correlation between "skills" and resistance to affirmative action. People with rare and highly specialized skills (me, for instance) aren't much threatened by gross racial quotas. There just aren't enough candidates for the kind of work we do from which to generate employment statistics by race, so in general nobody sees much value in worrying about it. (University teaching, where Diversity uber alles, is another matter.) But the other side is that social networks become much more important. Employers who might want to hire someone with my background are typically only going to higher one person, so it makes sense for them to use their networks to do it.
In contrast, down the skill chain, where there are a lot more positions and candidates to sort, employers rely much more on relatively straightforward metrics. I don't actually know, but I suspect that social networks play a diminished role. In contrast, however, racial quotas become much more of an issue. It is too easy for someone to notice -- and sue over -- racial imbalances. So the pressure to make sure the quotas are met increases.