Obama is becoming an embarrassment to blacks, that’s why they’re turning on him.
I’d be cautious in drawing too much confidence in these polling numbers. Remember there have been similar claims of dramatic drops in the support of Jews for Demo(n)-candidates but when push came to shove - they voted their ‘hearts’ over their own self-interest and rational choice by pulling the lever for the Demo(n)s, terrorist enablers and against Israel. There are still far too many who would rather ‘die’ or let others suffer and die than vote Conservative/ Republican.