Race is not simply skin color. It is a complex cocktail of genetic traits and hereditary conditions that create a genetic totality. To say race is a social construct would ignore the predominance of sickle cell anemia among Africans, or lactose intolerance in non-European populations, or diseases seen only in highly closed societies (until recently) like Jews and French Canadians. It can predict likelihood of diabetes, heart disease, cancer and a whole host of other things as people age. It affects drug tolerances and a lot of other things. Hell, it even affects what sort of barber you want to go to because European hair is different from Asian hair, which is different from African hair, etc.

Despite the inconvenience of the statement, race also appears to have an impact on IQ, which is very accurate in predicting future success in life. The reasons for that are not well understood because even acknowledging the fact elicits cries of racism, but it's there.

There are a lot of social consequences to the underlying genetic differences that probably can be mitigated or changed, such as crime rates by race or poverty by race, but just because there are social consequences doesn't mean race itself is a social construct. This is just wishful thinking.