Boy, this isn't how I think of interracial marriages.
I used to live in the Maryland suburbs of Washington, DC, where interracial couples are common and where, whether as cause or effect, there seem to be (as far I ever noticed), hardly any major racial issues or tensions.
My wife's sister lives in Memphis, where race issues are so thick you could cut 'em with a knife, but only if it was a sharp knife. (Incidentally, I think at least some of the reason for this is an entrenched core of race-baiters and bigots of both races who keep things stirred up as much as possible).
For me, an interracial child is a living symbol that skin color is ultimately quite a superficial difference. It's a symbol that people with differing skin colors, and different heritages, can genuinely love each other.
I live in Montgomery County, Maryland, one of the great things is that it is very diverse here and people are tolerant (in good and bad ways).