Where the homogeneousness comes from that doesn’t exist

Americans don’t find they got anything in common with each other, nothing really UNITES them. That’s why they need such opposing groups like women and men, black and white, Democrats and Republicans, LGBT and the majority of vanilla sexuality practitioners, Christian religion and all others (including atheism), hillbillies and academic cosmopolitans etc. or artificial enemy images lurking in the world outside the US which must be fought and not let inside their circle.
They need to artificially declare people to be homogeneous and put them into a drawer that actually isn’t as uniform as they pretend to themselves because otherwise they don’t find anything posing an overlap in personal interests that would generate a substantial reason to cooperate.