Hi Karen:

It's normative to marry a person of the opposite sex, and so it tells us very little about sexism. My argment is more like the argument that men who marry men are -- on average -- less homphobic than men who marry women. But I bet we agree that it is possible to be racist and to be in an interracial marriage. I think the question is whether, on average, White people in interracial marriages are less racist than White people in same race marriages.