black/white relations worse off than in 10 years - Maybe. Or maybe both sides are better at speaking up now. Good thing.
citizens of the US vs illegals - worse off - It was Trump, not Obama, based his campaign on dividing citizens and illegals. If anything Obama "improved" things by quietly deporting more people than any other president
rich vs poor - worse off - This divide has been steadily growing for far-longer than 10 years
southern confederate states vs the world - worse off - This wasn't even a known issue pre-Trump
athletes vs fans - worse off - What?
Christians vs muslims - worse off - I think there was something that happened in 2001 that set this one going
gays vs straight - worse off - Are you serious with this one? I don't credit Obama for it, but gay/straight relations are much better now than they've ever been.
civilians vs police officers - Yes, Obama helped make this relationship worse, by empowering the public to speak up. That's a good thing
I can't think of anything that's happened in a decade that we can say hey - yeah, we're all closer now in that areas/group. Can anyone? We are a nation divided.