I've always believed that, as a whole, the foreign contingent - even the Catholic Church , is more disposed to the idea (something about the cancer of this country .. Fighting for racism even if it means downfall. What do you expect from Hitlers mentors) ...
Check this out ...
I even ran across something on social media talking about the United Nations talking about it now ..
We'll see ..
My take on a possibility is that the Europeans that were in the slave trade in their colonies didn't have slavery in Europe. No one talks about why England, Spain, France, Portugal, etc who all had colonies with slaves didn't have their home country with slaves.
Two reasons I think. One is slaves would take the jobs of the poor in their country. But why not even a few. Say okay, 1000 slaves. That won't do any harm to the country's poor citizens. Why? They knew it was wrong. And it was an out of sight, out of mind thing. Same thing in the north in America. 90 percent of people in the 1700 and 1800 hundreds died within 50 miles of where they were born.
So, they have much more of a guilt thing. In America, white folks (in the south) lived among slaves. Experienced or heard of 100s of slave revolts. They built a society that changed culturally to one that was based in large part on keeping Blacks oppressed. No such social system occurred in Europe as there were hardly any Blacks and the people didn't see or hear much of what happened in the colonies that had slaves.
America is different. Caribbean is somewhere inbetween. Europeans freed their slaves way earlier than America did. England started freeing slaves as early as 1809 (when they also banned the transatlantic shipping of slaves) till its full end after 1830.
In America hating, fearing, oppressing Blacks is ingrained. And that mindset was de facto passed on to incoming European immigrants if they wanted to be accepted as American and have white status.