I’m pretty sure the conclusion is TG→D/H not the other way around. “When” which is a group one word introduces D/H.

How long between each section?

What role does the line, "An act or omission by one person is not right if such an act or omission done by large numbers of people would be socially damaging"?

Would the main point of the passage remain the same if this line were removed from the stimulus? I kind of see this line as necessary for making "people should vote" the main point, whereas without this line, "people should vote" would merely be most strongly supported.