How do Mandela's calls to action work to develop another central idea of his speech?

Those who are voteless cannot be expected to continue paying taxes to a government which is not responsible to them. People who live in poverty and starvation cannot be expected to pay exorbitant house rents to the government and local authorities. We furnish the sinews of agriculture and industry. We produce the work of the gold mines, the diamonds and the coal, of the farms and industry, in return for miserable wages. Why should we continue enriching those who steal the products of our sweat and blood? Those who exploit us and refuse us the right to organise trade unions?

the author develops a cold, and scared tone. making the reader shudder with fear, and suddenly become cold. i'm guessing that he's writing a scary novel, or maybe about a chilly december night.

the purpose of the heading in the passage is to identify who is telling the story.

this excerpt is part of the book sugar changed the world (2010) written by marc aronson and marina budhos. as the book has been written by two people, the heading "marc" indicates that this specific excerpt is being narrated by aronson. in the fragment, marc describes his grandfather's story after hearing it from his cousin. however, there are other excerpts where budhos is the one that tells the story of her family.

aronson and budhos, who are husband and wife in real life, decided to write sugar changed the world when they found out how sugar, which had an important role in slavery and economy, changed their ancestors' lives.