I'll look for something credible and send it to you if I can find any. I just know from reading and studying history that this kind of stuff is part of American culture. During the Revolution a large segment, possibly even a majority, of colonists were loyal to England. In the Civil War Lincoln was maligned in cartoons and editorials. His approval rating was probably in the 20s or 30s in the part of the nation that didn't seceed. Wilson, Roosevelt, and Truman also took huge amounts of criticism and were hated by large sections of the population.
You're probably right. Has the press also always been rooting for the other side? Maybe things aren't as bad as I think they are.
susie