After reading the lyrics i have a hard time thinking that is some sort of black national anthem. That sounds like the sort of prejudiced emotionally charged language that would come from right wing propaganda sites like stormfront. This is probably why i don't expect reliable news from stormfront.
If someone wants to put that flag on their truck, or someone else wants to sing this anthem on their own time, that's fine. Forcing either of these things on students in school is disgusting.
"If I take death into my life, acknowledge it, and face it squarely, I will free myself from the anxiety of death and the pettiness of life - and only then will I be free to become myself." ~ Martin Heidegger