What is the role of crime in Tortilla Curtain?

Examples:

"He flung open the door and shot through the courtyard, head down, rounding the corner of the house just in time to see a dun-colored blur scaling the six-foot chain-link fence with a tense white form clamped in its jaws. His brain decoded the image: a coyote had somehow managed to get into the enclosure and seize one of the dogs, and there it was, wild nature, up and over the fence as if this were some sort of circus act."

The Tortilla Curtain, 37

This quote describes Delaney running out of the door and after a coyote who had one of the Mossbachers' precious family dog, Sacheverell, in its jaws. However, it can also be read to desscribe the situation with Mexican immigrants. Like the coyotes, with whom they are associated throughout he novel, these immigrants jump over, crawl under, and generally evade the fences and other obstacles at the Mexico-U.S. border. They sneak in to make money and to find food for their families, and, as many angry American citizens see it, steal the resources of law-abiding Americans. Like this coyote, the immigrants vault over the fence, take what is not rightfully theirs, and then vault right back over.

"Delaney looked round at his neighbors, their faces drained and white, fists clenched, ready to go anywhere, do anything, seething with it, spoiling for it, a mob. They were out here in the night, outside the walls, forced out of their shells, and there was nothing to restrain them."

The Tortilla Curtain, 289

This quote comes immediately after Delaney has attacked the handcuffed José Navidad, arrested under suspicion of starting the fire. His furious, uncontrolled actions and unexplainable anger towards the Mexicans has incited a full-on riot, with the evacuated residents of Arroyo Blanco ready to attack anything and anyone. The idea of the wall has once again arisen, but this time the white people have been forced outside of their walls, outside of their comfort zones, and the result is frightening. They have abandoned their ordered ways, Delaney even abandoning his self-inflicted rules and indulging in alcohol, and have become more like the uninhibited immigrants that they loathed and feared so much.