The subtitle, from above:
"If you aren't willing to fight the culture war, your culture will be taken from you"
The culture they want to take away is one that was created almost exclusively over centuries by white Europeans.
It is the culture with which white, traditional-minded Americans "identify".
Thus, Fishrrman's dialectic:
You may not be interested in the politics of race, ethnicity, and identity.
But the politics of race, ethnicity and identity are VERY MUCH interested... in YOU.