I do not thing this phenomenon of mixing crude manners, anti-intellectualism, smart alec attitudes and populism is uniquely American. Stalinist propaganda of 1950s and Maoist propaganda of 1960s (I had the dubious pleasure to eyewitness both, but also see Andrzej Wajda's film 'The man of marble" and Milan Kundera's novel "The Joke") used pretty much the same mechanisms. I also understand that the Nazis used such mechanisms too cf. the notorious Hanns Johst quotation "when I hear about culture I cock my gun" (Wenn Ich Kultur hoere, entsichere Ich meinen Browning).
The mechanism at work here is that every elite needs popular support to stay in power, and to attract that support it needs to tie in one way or another its own interests to those of the masses. Stated differently, the masses must identify with the elite in some way to follow it.
There are many ways to accomplish that goal, some involve giving some tangible benefits, other - symbolic rewards and still other - giving indulgences. Since tangible benefits (cf. welfare state in Bismarck's Germany) cost money, the elite prefer the latter two.
Symbolic rewards usually involve the official elevation of popular characters or common folk ways cf. politicians wearing a firefighter's hat, using vernacular, or being "folksy." Cf. Clinton plying saxophone, Bush speaking Spanish or wearing cowboy boots, Mao Tse tung swimming across the Yangtze River and kindred spectacles showing the masses that the glorious leader is really "one of us."
Giving away indulgences usually involves official permission to engage in hitherto prohibiting behavior that can create a sense of personal power. Thus, in the Stanford Prison Study (and the film 'Das Experiment"), the "guards" are given a permission to oppress the "prisoners' which given them the immediate gratification in the form of feeling more powerful. In real life, giving away indulgences may take the form of lynchings or pogroms that receive some form of official blessings. Another form is vicarious participation in the expression of power is public humiliation, torture or executions of selected enemies of the ruling class (cf. Michel Foucault, _Discipline and punish_). Some feminist scholars also argue that giving the men the power over "their" women was the means of subjecting them to the control of power elites.
To summarize, the elite must tie its own interests to those of the masses to command authority over them. Of the many means to accomplish that, those that the least expensive (for the elite) is the symbolic anointment of popular characters of values by official figures and the official figures endorsing or encouraging the masses to go on power trips by denigrating despised minorities.
Another thought - HL Mencken was right saying that all that the "masses" want is the privileges that they are unwilling to give to other people. It follows that the "masses" will be complaining bitterly when they get what they unfair treatment, but have no reservation whatsoever to give the same treatment to someone else. Thus, a white male cries "discrimination" when he does not get a job he wants, but he has no problem when women or minorities do not get jobs they want. That is why populism is socialism of fools.
Wojtek