Progressive's were some of the biggest proponents of eugenics, naturally. WSJ: The Progressive History of Eugenics.Anti-miscegenation amendments to the Constitution were all attempted by Democrats: https://en.wikipedia.org/wiki/Anti-...-miscegenation_laws_and_the_U.S._Constitution
Today, racial segregation, which occurs most in democrat-controlled cities, has the most influence on inherited IQ.
That said, I'm not sure how anti-miscegenation laws affect iceaura's most recent argument: "White racism affects the IQ of black people in the USA."
Firstly, a lot of white, yellow, black, and red Americans are mixtures of white, yellow, black and red people. For example Science: Genetic study reveals surprising ancestry of many Americans.
In the United States, almost no one can trace their ancestry back to just one place. And for many, the past may hold some surprises, according to a new study. Researchers have found that a significant percentage of African-Americans, European Americans, and Latinos carry ancestry from outside their self-identified ethnicity. The average African-American genome, for example, is nearly a quarter European, and almost 4% of European Americans carry African ancestry.
The average African-American genome, for example, is 73.2% African, 24% European, and 0.8% Native American.
What exactly is your argument iceaura? That African-Americans would have a significantly higher percentage of European ancestry (and therefore higher IQ) if not for these laws? Is that your argument?
My guess is, the number of people who would have engaged in so-called inter-racial marriages would have been minimum. Statistically, insignificant post-civil war. Further, none of these laws are in effect today, and so the laws do not affect modern day Americans.
That said, this is a great example of Progressive Socialism. Where the State is employed against morally innocent humans for the supposed 'good of society'. In this case, the State was used as a weapon against individual's and their personal relationships (this included laws against marrying yellows and whites, blacks and native Americans, and etc...). You know what the craziest thing is? I would not doubt, given the insanity of the Left in modern politics, that such laws don't come BACK into effect in the future. Given the whole polemic regarding 'Cultural Appropriation' don't be surprised if 'evil racist whites' aren't legally prevented from 'mixing' / appropriating the genetics of minorities via similar laws.
THAT'S the level of insanity we now see coming out of the progressive left. Which, makes good sense, given their racist history.