Vance marrying a Hindu Indian isn't great, but taking huge issue with individual choice isn't great either. The important thing is what he's doing to change the course of the population at large, which is always deterministic.

Most of the top players in the alt right are actually some level of mixed or non-white, as weird as it is. There's probably some social phenomenon there about people on the edge being more equipped to perceive and act on cultural taboos.