There are still plenty of people who are uncomfortable with the concept of a mixed race marriage.
Here's my story about it: Wa-a-a-ay back in the late 60's, there was a front cover story in TIME magazine regarding mixed race marriage. I don't recall who was featured on the cover, but she was the daughter of some high-ranking Washington DC official and she was marrying a black man.
If I strain my brain, I would have to guess that he was a West Point cadet, that she had met at some official event. But whoever he was, the point is, he was no low-life slacker.
So TIME did the story, and my mother made a point of talking to me and my sister -- neither of us old enough to date at the time -- about it.
I clearly recall that she told us that IF either of us were to fall in love with and wish to marry a man who was not of our ethnicity -- a "non-WASP" that is -- neither she nor my father would object, assuming we truly believed that we were in love.
But she wanted us to be sure to understand that NOT EVERYONE would be so accepting of our relationship, and we would have a tougher time going through life. Marrying outside of our race, she concluded, was not prohibited in our family, but it was not advisable, either.
Looking back on this discussion now, I see that my mother's thinking was quite liberal for the times. And, I suspect that the fact that she and my father had experienced social challenges in their lives, due to the fact that she was adopted into a family that was viewed socially as "high society," while my father was simply the handsome, intelligent son of a hard-working Scandinavian immigrant who had come to the US with nothing, worked hard, become successful -- the traditional "up from the bootstraps" stuff.
There is an old family story that my two sets of grandparents met, once they became aware that their children were dating, and strategized on how to keep my parents apart. Something that may have happened more in the early 50s than it does now.
As a result of all that parental meddling, my mother became a champion of the concept that love must triumph.
So like mother, like daughter I raised my children the same way, and I expect my sister did as well. I haven't really talked to her about her personal feelings on my niece's choice of husband. Outwardly the families are supportive.
But I think the stories told by the parents at the reception - regarding how Kate and Lavar introduced their parents to the importance of the relationship, shows that here in the US, social mores haven't changed that much since the 60s.
If they had, this part of the "niece getting married" wedding story wouldn't even be under discussion.