Not one fact to support her claim. The 10% figure is probably about right, given that Blacks constitute about 12% of the US population. Yet another example of how dumb people don't know crap about statistics.
The root issue to liberals is “it is white dominated, therefore bad”. This is similar to hating on the hard sciences for being mostly male, but there’s no problem with the life and social sciences being female dominated.
It is mostly white, therefore it is inherently bad and must be shamed, shut down and/or reformed to exclude whites.