A leading Presidential candidate has presented an immunological concept. In order to maintain the nation’s boundaries, a wall must be constructed—and laws passed—to prevent “foreign elements” from entering the nation. Donald Trump equates his own body with the American body politic—and assumes other Americans do so as well. The danger is that “porous boundaries” will allow alien elements to seep in. In advocating the creation of firm, solid borders, nationalists seek to create a less vulnerable body—one not so easily penetrated or violated. At the heart of the immune system is its function distinguishing self and nonself. The immune system is the “ever-vigilant protector of the environment of the body” (Martin, 1999). Anything foreign that dares to invade this environment must be “rapidly detected and removed.” The immune system identifies cells that “belong” to the body—in contrast to cells that are foreign—do not belong. These alien cells must be rejected or destroyed. Nations—like bodies—possess sharply defined boundaries, and frequently are imagined to be besieged or threatened. The imperiled nation must “continuously work to quell alien invaders” (Martin, 1999). When a nation feels that its boundaries are porous, it may seek to create walls—or other impediments—to prevent alien or foreign cells from entering the body politic. Nationalism becomes a form of immunology. University of Berlin Professor Eugen Fischer asserted in a lecture on June 20, 1939 (see Lifton, 1986) that when a people wants to preserve its own nature it must “reject alien elements.” When these elements already have insinuated themselves, the people must “suppress and eliminate them.” The Jew, Fischer declared is such an alien, and therefore when he wants to insinuate himself he must be “warded off.” Such actions were merely self-defense. “I reject Jewry,” Fischer concluded, “with every means in my power.” Hitler and the Nazis treated the German nation as if a body with an immune system that recognized what is “self” and rejected what is “not-self.” Identifying Jews as foreign or not-self cells within the German body politic, the national immune system acted—could not do otherwise but to act—to “reject” or destroy these alien entities. In Mein Kampf (1924), Hitler posed the question, “Could anyone believe that Germany was not subject to exactly the same laws as all other human organisms?” Conceiving of Germany as a living organism, Hitler was suggesting that—like any other organism—the nation possessed an immune system that would automatically destroy entities identified as foreign. In the United States today, a leading Presidential candidate has presented and conveyed an immunological concept. In order to maintain the nation’s boundaries, according to Donald Trump, a wall must be constructed—and laws passed—to prevent “foreign elements” from entering the nation. Nazi philosopher Alfred Rosenberg stated (1970) that the spirit of a race realizes its ability to “assimilate everything racially and spiritually akin,” and at the same time to “eliminate and suppress everything foreign.” Members of alien groups must be prevented from entering the body politic because they are “out of tune with our kind and violate the inner construction of our being.” Donald Trump, it would appear, equates his own body with the American body politic—and assumes that many other Americans do so as well. These Americans bind their existence to “geographic space” (Stein, 2013). The danger is the existence of “porous boundaries”—that allow alien elements to seep into the national body. In advocating the creation of firm, solid borders, nationalists seek to create a less vulnerable national body, one not so easily penetrated or violated by foreign bodies.