Which quotation from the speech best develops the central idea that african americans have been regularly denied their rights? "our lives have been marked with debate about great issues, issues of war and peace, issues of prosperity and depression." "the history of this country in large measure is the history of expansion of the right to all of our people." "experience has clearly shown that the existing process of law cannot overcome systematic and ingenious discrimination." "it really rests on his right to be treated as a man equal in opportunity to all others."