David Warren writes a must-read:
Morning papers circulated chiefly in the city cores, among a readership more liberal, and tended to be Democrat. Evening papers circulated more beyond the city, among a readership more conservative, and tended to be Republican. But from any given city, there were two distinct party points of view, and better-informed people read both newspapers. (…)
The loss of those evening papers, and their replacement with network TV news, and other national media such as newsmagazines — guided ultimately by the attitudes of editors and directors in New York City — helps to explain what happened.