America in one way or another has always been that way. Look at the political election debates of Adams and Jefferson, or Lincoln. People certainly did demonize others back then.

Live in little security? Murders were just as rampant in the big cities of the past as they are today. Same with corruption. Look at the histories of Chicago, New York, St. Louis, Los Angeles, etc. When this country was founded it was a country that enslaved people. It cheated native peoples out of land and murdered them. Where was the civility for them?

There were more manners in a general sense that came out of Victorian influences, but since the 1890s there has been a dechristianization of America in the courts and all other branches of government. During the flapper era of the 1920s there was a decrease in civility and a resurgence during World War II until the mid-1960s.

Much of today's left-wing political ethic derives from Herbert Marcuse and the Frankfurt School of Marxism. They helped create the New Left, which dominated the media and Democratic politics. It influenced education, which went from focusing on the three R's to self-esteem. All together it helped create a sense of entitlement. There is also a modern definition of equality that comes out of the French Revolution that focuses on result rather than opportunity, and this prevails everywhere.