Edit for context:
My view is transracial isn’t valid and this person is trying to dogwhistle. I’ve already blocked this person, and now they’re going after my friend saying my friend is transphobic because they disagreed with them about transracial being a thing (they’re purposefully leaving the context out so my friend looks transphobic when what my friend really said was transgender is valid but transracial isn’t)
“A social construct is an idea, category, or framework that gains meaning through collective agreement within a society”
The racial lines of division are arbitrary and different in each society. Therefore, a social construct.
Remember, it wasn’t THAT long ago that Italians weren’t considered white. Now they are.