He is setting up a legal maneuver. Once it becomes about “race” the burden of proof is on the accused.
So if he says that only racists disapprove of Obama and the DOJ, he can start prosecuting those who disapprove on hate crimes.
The trial balloon is the float makes in Nebraska. If/when they get charged with some sort of hate or civil rights crime, then you can expect a move against all who disagree.
For a generation or more the Race Card has been used to trump all facts and rational discussion.
Holder is just trying to inculcate feelings of white guilt by playing the Race Card in an effort to cut off any more valid criticism (and investigation) of the criminal Obama administration,
"Hey Look! Over Here - A Racist !!
But the Race Card and charges of racism have been overplayed to the point they don't have the impact they once had.