"President Schwarzenegger" was actually a disguised Rainier Wolfcastle
In the Simpsons universe, Arnold Schwarzenegger
does end up successful enough to get elected president, but he eventually decides that he's tired of the stress of politics, and he misses his simpler days as an action star. Meanwhile, Rainier Wolfcastle decides that he's tired of being seen as a brainless action star, and wishes that people would take him seriously. One day, he meets Arnold Schwarzenegger by chance, and they both realize how much they resemble each other. Realizing that each has the life that the other wants (a carefree life as a movie star for Arnold, power and respect for Rainier) they switch places à la The Prince and the Pauper
A company that is involved in agriculture, pharmaceuticals, risk management, electricity and gas. The company is still owned by the Cargill family.
Russ Carill is in fact an alter ego of Hank Scorpio, having infiltrated the USA government.
The entire film is a hallucination created by Grampa
His line "A twisted tail, a thousand eyes, trapped forever, EPA EPA!", said while having a seizure at church seems to refer to Plopper, the mutant squirrel created as a result of Homer placing Plopper's pig crap slio into a lake
and the dome respectively. But what if he's not accidentally predicting events shown later into the film?