If you want to make an impact while delivering a political message, use a black Baptist preacher. This was from African American Heritage Celebration. I've always admired the preaching and gospel singing in Afro-American churches. Their vocal intonation, their rhetoric, their histrionics and body language make for inspirational and entertaining listening.
For a mainly white audience to appreciate what it's like to be black in this country, just listen to a balck preacher, they'll let you know - succinctly yet powerful.