Cohen has two main sources of inspiration: a low cunning about what will puzzle, shock, offend, or outrage people and a live-comedy genius for taking his victims slowly, by degrees. In one sequence, Borat has wangled a gig singing the national anthem from the center ring of a rodeo. Before starting, he offers cheers for the current President Bush, which begin relatively innocuously and then head downward. When he sees that he can get away with, "I hope you kill every man, woman and child in Iraq, down to the lizards!" he sinks further, exulting, "May George W. Bush drink the blood of every man, woman and child in Iraq!" You can practically see Cohen thinking, Are they ready for this next one? Will this be too much?
Eventually he starts singing — the tune of "The Star-Spangled Banner" but the lyrics of the supposed Kazakh national anthem, which, boasting of the country's superior potassium, sounds like something by Tom Lehrer. And eventually the crowd begins to boo. It's theatrical genius: Cohen has devised a split-level act in which being hooked off the stage by his in-the-movie audience makes for success with his at-the-movie audience.
Cohen's shtick is almost entirely opportunistic; far too much has been made of the content of what Borat says and elicits from his victims. Most of the humor that doesn't derive from the tension of live encounters with unwitting participants is dialect humor about the simplicity and backwardness of immigrants, which was a staple of the vaudeville circuit. And the fact that the rodeo audience seems at first to go along with Borat's zany oratory doesn't tell you anything besides the fact that an audience hearing something so out of the ordinary will react slowly, because it's out of the ordinary and because there can be a certain inhibition among members of a relatively random group. Cohen thus makes possible some highly unusual sociological observation, but the comic substance resides solely in what he's saying and doing.
True, Cohen, an observant Jew, lampoons peasantly Old-World anti-Semitism in the carnivalesque "running of the Jew" in Kazakhstan and in Borat's fear of the Jewish-American owners of a bed-and-breakfast where he stays. (He remains wide awake in bed, clutching dollar bills to throw at his hosts so they won't harm him. When two cockroaches (released by the filmmakers) scurry under the door, he throws bills at the supposedly shape-shifting Jews and runs for his life.)
Thus, there's a strand of satire in Borat, but the majority of the set-ups, including the rodeo scene, which begins with Borat leading the organizer on to make homophobic remarks, and the dinner party at which Cohen pretends not to know how to use an indoor flush toilet, are not examples of it. Not even the infamous RV ride, in which three South Carolina frat boys get drunk and make moronic comments about "minorities" and women, is satiric. How could it be—Cohen didn't know what they were going to say until he got them to say it. Satire, by contrast, implies militant intention on the author's part. There may be a satirical purpose in Cohen's selection of clips, but that's pretty weak as satire goes because it doesn't permit enough distortion. (Dryden, for instance, doesn't let Shadwell speak for himself, however ill, in MacFlecknoe, because the target of his scorn would never have worked out a caustic, mock-heroic caprice featuring himself as the King of Nonsense's successor, "[m]ature in dullness from his tender years.")