If it comes to anything concerning race or ethnicity, I have to say I do not know. Global Warming was a fact before the polarization of the country/world, but I did not delve into anthropology and I'd be a fool to think that there is no chance they do not only accept facts that adhere to their world view. 

For example, I was talking to my friend about some very odd people who were complaining that the new game Kingdom Come: Deliverance doesn't have enough black representation when the game is set in early 15th century Bohemia, and the entire thing occurs within a 9 mile radius. As a historian I knew what they were arguing was, to put it bluntly, horseshit. But when I googled it as a curiosity, all I found were biased articles on both sides that brought little evidence, and I realize you can't even look up medieval demographics anymore without it having a political agenda. 

Pretty much, unless I read an article that tells me there is/isn't a reason to think of ethnicity or race as a social construct that provides evidence and sources I can believe (or just takes some courses myself), I'll just give an honest "no idea." Either way, even if it wasn't a social construct that doesn't mean it would justify the mistreatment of others.