"Race" is a proxy for social class.
I think (but don't know) that people would have less problems dating other people from another race who are of the same social class as themselves or above, than they would date people of the same race but from a lower social class.
You mean, "social class" is a politically correct term used to explain the general differences between races.
Asian men tend to do very well in school and careers and typically have a higher than average income, yet they are considered less attractive than Latinos, who generally perform much lower in school, career, and have a lower income than Asian people.