Our country elects its first black president and the response by mostly white republicans (I am white) is to block every move Obama plans to make.
http://www.pbs.org/wgbh/frontline/article/the-republicans-plan-for-the-new-president/
Then, those same Republicans and their constituents vote for a lying, rich white guy claiming this country is a hellhole and claiming he and the "others" must "take back" their country and "make america great again". This elected buffoon has accomplished absolutely nothing in his 9 months in office, sans saying nazis were "good/fine people" and categorizing black citizens exercising their rights as Americans as "sons of bitches".
If you want to talk about divisiveness, you can start with the moron in office that said our first black president wasn't born in this country... and he led the investigation, claiming "you won't believe what we are finding in Hawaii"... years later this moron admitted it was all bullshit, but it just so happens the seed of divisiveness and hate for the person in office had already been planted. The moron rode that divisive wave (your wave) of emotions and lies straight to the white house.