I hardly know where to start in responding to this ideological blast. So let me go to the end, where Mark mentions the "bitterly opposing factions" his piece describes.

Republican and Democratic partisans certainly do think ill of each other in many respects, and resort to dishonest trickery in attempting to prevail in legislation and elections. This partisanship long predates Trump; indeed, it traces back to the rivalry between Adams and Jefferson, the enmity of Jackson and John Quincy Adams, and so forth.

A major difference now, though, is that propaganda propagates much more readily. This is due largely to the lack of personal relationship between voters and politicians. Formerly, voters had important ways to know the politicians. But with population growth, universal suffrage, and civil rights the pool of voters is vastly larger, so few voters have any first hand knowledge of the character of Statewide or federal candidates. Nor is second-hand knowledge widespread, since few people today personally know a labor leader, a clubhouse politician, or any other civic leader. Fewer still would trust their wisdom in supporting one or another politician's character. Consequently, the web of personal knowledge that could withstand slanders and false news reports has greatly diminished.

Instead, we are dependent for our knowledge of politicians on distant media. Even for the most knowledgeable of us, our ability to determine media credibility is limited. Moreover, even for clearly truthful claims of personal immorality, the relativistic moral climate of the day has persuaded many people that party loyalty trumps character in the voting booth. The harsh moral judgments of yore were often unkind and unfair, but they were pretty clear. The somewhat successful late 20th century liberal quest for more fairness has made moral judgments fairer on the whole, we have also made them harder to apply to any given individual. These days, sexual misconduct does not disqualify candidates from public office, even in the eyes of moralists like the Evangelicals.

Additionally, people rely much more on "experts" for their understanding of public policies than used to be the case. The issues are now seen as far more complicated than before, so people understandably take their views from those they regard as more knowledgeable. Unfortunately, the most persuasive "experts" are those whose expertise lies in presentation, rather than substance. And critical to persuasive presentation is simplicity. So conservative broadcasters, preaching simple dogmas, have a great advantage over liberals, whose ideology is rooted in an acceptance of complexity. I think that helps explain why a recent study reports that falsehoods propagate through social media much faster than truth.