I wouldn't say Obama caused it, but he did nothing to help the situation IMO. Yes, LBJ's policies sure helped to destroy the black family unit.
He fed them a ton of BS...that claimed he was helping them, when all along all he wanted was some cheap votes!
By the time Bush #41 left office, race relations were going along quite well, andfew there were who wanted to be bigots...stirring things up again.
Then people mistakenly elected a "community activist" as a president! What the &^#+% did they expect they would get... a nice, peace promoting guy?