>But most of us (to my knowledge) also agree that while race
>is a social construct, there are material
>benefits/consequences for ones race. We have made those real.

But u have articulated a key distinction.
Race though man-made does have a dependent relationship on lineage. But then what about mixed kids? They may or may not experience the historical context of their given lineage often based on self-identification and physical appearance. Physical appearance also has a close relationship with race which makes it murky again.