In City Journal, Victor Davis Hanson says the rise of Trump and other populist politicians is being powered by lower- and middle-class rejection of the elite preference for open borders:
Driving the growing populist outrage in Europe and North America is the ongoing elite push for a borderless world. Among elites, borderlessness has taken its place among the politically correct positions of our age — and, as with other such ideas, it has shaped the language we use. The descriptive term “illegal alien” has given way to the nebulous “unlawful immigrant.” This, in turn, has given way to “undocumented immigrant,” “immigrant,” or the entirely neutral “migrant” — a noun that obscures whether the individual in question is entering or leaving. Such linguistic gymnastics are unfortunately necessary. Since an enforceable southern border no longer exists, there can be no immigration law to break in the first place.
Today’s open-borders agenda has its roots not only in economic factors — the need for low-wage workers who will do the work that native-born Americans or Europeans supposedly will not — but also in several decades of intellectual ferment, in which Western academics have created a trendy field of “borders discourse.” What we might call post-borderism argues that boundaries even between distinct nations are mere artificial constructs, methods of marginalization designed by those in power, mostly to stigmatize and oppress the “other” — usually the poorer and less Western — who arbitrarily ended up on the wrong side of the divide. “Where borders are drawn, power is exercised,” as one European scholar put it. This view assumes that where borders are not drawn, power is not exercised — as if a million Middle Eastern immigrants pouring into Germany do not wield considerable power by their sheer numbers and adroit manipulation of Western notions of victimization and grievance politics. Indeed, Western leftists seek political empowerment by encouraging the arrival of millions of impoverished migrants.