I'm not sure how many organic intellectuals make it into journalism / non-fiction (given the essentially conservative nature of the publishing industry), but writers, musicians, artists from the working class frequently develop a consciousness and an eloquence that fights the power. Your mention of Harry Haywood reminded me of the short story "Solo Song: For Doc" by James Alan McPherson, which explains the power of systemic racism as thoroughly as any book-long treatise on the NYT Bestseller list.