On Wednesday the Biden administration announced that it will offer work permits and deportation protections to over 400,000 Venezuelans who have arrived in the United States since 2021. On paper this is a humanitarian gesture, a recognition of the miseries of life under the Maduro dictatorship. In political practice it’s a flailing attempt to respond to a sudden rise in anti-immigration sentiment in blue cities, particularly New York, as the surge of migrants overwhelms social services and shelters.

I say flailing because the fundamental problem facing the Biden administration is on the southern border, where every attempt to get ahead of the extraordinary numbers trying to cross or claim asylum has been overwhelmed.

In Eagle Pass, Texas, The Wall Street Journal reports that in a week, an estimated 10,000 migrants have entered the city, whose entire population is less than 30,000. The subsequent movement of migrants to places like New York, Chicago and Washington, D.C., has been encouraged by red-state governors, but under any circumstances such crowds in Eagle Pass would eventually mean rising numbers in big cities. And policies that make it easier to work in those cities, like the Biden move, are likely to encourage more migration until the border is more stable and secure.

The liberal confusion over this situation, the spectacle of Democratic politicians like Eric Adams and Kathy Hochul sounding like Fox News hosts, is a foretaste of the difficult future facing liberals across the Western world.

For decades, liberal jurisdictions have advertised their openness to migrants, while relying on the sheer difficulty of international migration and restrictions supported by conservatives to keep the rate of arrivals manageable, and confine any chaos to the border rather than the metropole.

What’s changed, and what will keep changing for decades, are the numbers involved. Civil wars and climate change will play their part, but the most important shifts are, first, the way the internet and smartphones have made it easier to make your way around the world, and second, the population imbalance between a rich, rapidly-aging West and a poorer, younger Global South, a deeply unstable equilibrium drawing economic migrants north.

All of this is a bigger problem for Europe than the United States — European aging is more advanced, Africa’s population will boom for decades (in 50 years there may be five Africans for every European) while Latin America’s birthrates have declined. The European equivalent of Eagle Pass is the island of Lampedusa, Italy’s southernmost possession, where the number of recent migrants exceeds the native population. This surge is just the beginning, Christopher Caldwell argues in an essay for The Spectator on the continent’s dilemmas, which quotes a former French president, Nicolas Sarkozy: “The migration crisis has not even started.”

America’s challenge is less dramatic but not completely different. The world has shrunk, and there is no clear limit on how many people can reach the Rio Grande. So what’s happening this year will happen even more: The challenges of mass arrivals will spread beyond the border, there will be an increased demand for restrictions even from people generally sympathetic to migrants, but the sheer numbers will make any restrictions less effectual.

This combination can yield a pattern like what we’ve seen in Britain after Brexit and Italy under Giorgia Meloni: Politicians are elected promising to take back control of borders, but their policies are ineffective and even right-wing governments preside over high migration rates. The choice then is to go further into punitive and callous territory, as the Trump administration did with its family-separation policy and its deal with Mexico — or else to recoil as many voters did from Trump’s policies, which encouraged the Democrats to move leftward, which left them unprepared to deal with the crisis when they came to power, which now threatens to help elect Trump once again.

In a sense you might distill the challenge facing liberals to a choice: Take more responsibility for restricting immigration, or get used to right-wing populists doing it for you.

But in fact the problems for both left and right will be messier than this. The populists themselves will not always know how to fulfill their promises. The interests of liberals in immigrant destinations like New York City may diverge from liberals in college towns or suburbs. The scale and diversity of migration will create unexpected alliances (a lot of Venezuelan migrants might vote for Trump if given the chance, after their experience with socialism) and new lines of internal fracture.

Most likely there will be neither a punitive end to the crisis nor a successful humanitarian means of managing it. There will be a general rightward evolution, a growing tolerance for punitive measures (“Build the wall” could be a liberal slogan eventually), that has some effect on the flow of migration — but doesn’t prevent it from being dramatic, chaotic and transformative, on the way to whatever new world order may await.