In a speech to fellow Republicans in Chicago in December 1856, Mr. Abraham Lincoln said: “Our government rests in public opinion. Whoever can change public opinion, can change the government, practically just so much. Public opinion, or any subject, always has a ‘central idea,’ from which all its minor thoughts radiate. That ‘central idea’ in our political public opinion, at the beginning was, and until recently has continued to be, ‘the equality of men.’”