Fear and a recognition of something are my guesses. They recognize truth in what's being said, they recognize that their position of power is at stake. In psychology, there's a principle called "extinguishment." Basically. it means bead behaviour gets worse before it stops. Take a toddler's tantrum, for example, before it stops, the kid wails at the very top of his/her lungs. Same thing here, the more we speak up, the more we demand our rightful place, the more we seem to be gaining any sort of traction, they make great efforts to shut it down, they see their systems of racism which benefit them and only them crumbling slowly and are terrified and as such, can't leave us alone.