Say what you may about Obama's progressive policies, he was a man that was articulate, diplomatic, professional. Something Trump will never be, but for some strange reason the supporters don't care about civility and diplomacy.
I remember when Obama shot off at the mouth saying cops acted stupidly, spurring on more irrational hatred of police, only to find out later that he should've taken the time to read the facts before opening his mouth. I don't recall him ever apologizing, unless you call the "beer summit" an apology.