Outside the human race? They are marrying Leftists? Yikes.One out of every eight people, are marrying outside their race. Genetic diversity gives the human population resistance to germs. Humans are very inbred, because of a genetic bottleneck, 80 thousand years ago.
If we can get the races all mixed up, people with high intelligence, will be more likely to thrive, and the people with low intelligence won't know about it, because the races will be all mixed up. Let's say, for argument's sake, that whites and blacks have 100 intelligence in common, and blacks have 50 intelligence genes that whites don't have, and whites have 75 intelligence genes that blacks don't have. If a black person and a white person then have a baby, it will have between 100 and 225 intelligence genes. Good genes spread faster then bad genes, through the population, because they are more fit to survive.
Reverse psychology may the best strategy, so we may want to tell young people not the marry outside their race.