In The Tortilla Curtain, to be American means to be overcome with fear regarding the reality of immigration. Boyle raises significant questions about whether this insecure mindset towards immigration can effectively address it.
Boyle uses the Mossbachers as representative of the modern American identity regarding immigration. Inside the comfortable world of Arroyo Blanco Estates, immigration is spoken about in positive terms. Boyle shows that people like the Mossbachers hold an abstract approach that is rooted in the "not in my backyard" approach. As long as the issue of immigration is away from them, it is viewed as an acceptable aspect of American life.
Boyle shows that when challenges arise, American identity takes a fearful approach towards immigration. The Mossbachers abandon liberal optimism and embrace a darker approach to immigration when economic and social issues present themselves. They view immigration as a threat to their lifestyle and their world. The Mossbachers accept nativist generalizations about immigrants such as "the more you give them the more they want, the more of them there are" or "they were ubiquitous, prolific as rabbits," and "they were death for business" as truth. Boyle suggests that when economic and social interests are threatened, American identity becomes inwardly drawn, retreating to fear about immigration. No better is such pessimism shown than in the community's desire to build the wall. When Kyra and Delaney accept the need for the fence to wall off the community, it is clear that it is more psychological than anything else: “This is a community . . . an exclusive private highly desirable location. And what do you think’s going to happen to property values if your filthy coyotes start attacking children.”
Boyle shows how the desire to build the wall around Arroyo Blanco Estates reflects something deeper about American identity. The wall is rooted in the desire to keep immigrants out. However, it also reflects a desire to stop the world's changing dynamics. The community's residents cannot accept the reality of a changing world:
... All Delaney’s neighbors could talk about, back and forth and on and on as if it were the key to all existence, was gates….To be erected at the main entrance and manned by a twenty-four-hour guard to keep out those very gangbangers, taggers and carjackers they’d come here to escape.
American identity is depicted as a flight from a changing world. Rather than seek to understand it, American identity is shown to run from it. Boyle views the Mossbachers as part of the growing demographic incapable of effectively dealing with a changing America. It is an America that looks, behaves, and expresses itself differently than it did in the past. Struggling to adapt to this difference is another part of how Boyle sees American identity in the modern setting.
The Tortilla Curtain raises questions about immigration and national security. One centers on the role of wealth. Boyle's depiction of the Rincons and the Mossbachers is a tale of two different realities. The consolidation of economic wealth in the world of Arroyo Blanco Estates is a stark contrast to the world that Candido and America experience. Even though both couples live in America, they experience two different realities. The natural question is why there is such an intense consolidation of wealth in the richest country in the world. Certainly, there can be more effective ways of reaching people who have come to America. There must be paths to successfully integrate new arrivals into our national tapestry and economic workforce. Instead of reaching out and attempting to bring in people like Candido and America, who want to be a part of the nation, Boyle shows the America of Arroyo Blanco Estates trying to wall itself off to protect "property values." The issue of economic marginalization is a part of the immigrant experience in The Tortilla Curtain.
Boyle shows how the people of the Arroyo Blanco Estates hold prejudicial attitudes towards those who have entered the country. These discriminatory beliefs can connect to national security. Candido and America have no other hope than to find their own piece of the American dream in "El Norte." However, Boyle shows that the rejection they face at the hands of the people like the ones who live in the Arroyo Blanco Estates could have a profound impact on national security. Being seen as "rabbits" or "death for business" takes a toll. Over time, people filled with hope about America might become disenchanted with it. As a result of being seen as "the other" or as an "outsider," such individuals might embrace criminal activity, and actions that could harm national security.
Boyle argues that the inwardly drawn approach of building a wall does not solve the challenges that immigration poses. No wall can prevent the wildfire that threatens the Arroyo Blanco Estates community or can offset the mudslide that causes Candido to save Delaney. Boyle argues that we must embrace solutions that emphasize outreach and an inclusion of voices in order to effectively address issues of national security arising from immigration. The story shows how inward approaches that underscore fear will not work. A real threat to national security can be seen when Delaney takes a gun to find Candido. When citizens walk around with guns looking for people like a hunter would for prey, national security is threatened. Such a reality is an extension of the inward approach to immigration. Boyle shows that accepting fearful and demonizing approaches to immigration could harm national security.