Well, it's happened, despite the fact that interracial marriages are legal:

A Louisiana justice of the peace said he refused to issue a marriage license to an interracial couple out of concern for any children the couple might have. Keith Bardwell, justice of the peace in Tangipahoa Parish, says it is his experience that most interracial marriages do not last long. [snip] “I don't do interracial marriages because I don't want to put children in a situation they didn't bring on themselves,” Bardwell said. “In my heart, I feel the children will later suffer.” If he does an interracial marriage for one couple, he must do the same for all, he said. CNN

This just adds to the urgency of a need to ensure that the personal opinions of the state's employees and representatives are not an acceptable reason for any preventing the marriage of consenting adults, who do not have a current and valid licensed marriage to another person.  Next we'll have observant Catholics refusing to marry a couple in which one member is divorced from a previous spouse who is still alive; orthodox Christians who refuse to marry inter-faith couples unless they swear to raise their children Christian, etc.