@sir82: It's undisputed that racial tensions before Obama took office were better than when he left office. Nothing is perfect, there will always be issues between various groups of people. A lot of people though quite correctly that racism was over when we elected a black President, it showed the world, that regardless of your upbringing and race, you can aspire to get to be the most powerful man on earth.
Obama subsequently shat all over that idea and said that racism is getting worse, that voting and accepting black people was not sufficient, no you were to submit to the black man, pay him reparations, let him take your property, your job and everything else because he was owed it because his ancestors experienced racism. The black man was never wrong, it was always an underlying racism and white supremacy to blame for every wrong, every crime and every outcome.
As a result you have people increasingly segregating themselves, you have increased black-on-black crime, situations in the 'hood' are getting worse and increased unemployment across black people. No longer were you allowed to look at a black person's criminal record when hiring (outlawed under Obama), so employers started using names and race as proxies to the likelihood of people being a criminal. Left-wing policy trying to correct perceived wrongs has always, always damaged more. This is true in environmental issues (nuclear bans -> increased coal usage), in political and societal issues.