Between 1890 and 1905, my four grandparents came to the United States fleeing poverty and oppression in Austrian Galicia and the Czarist Pale of Settlement. When I write about immigration, I imagine them looking over my shoulder. This isn’t sentimentality; it is a moral requirement. Remember that you were strangers in the land of Egypt. Remember that you were refugees in America.The story of immigration to America goes a long way toward defining the kind of country America is and explaining why it is different from most other countries. An Anglo-American settler population, having displaced the Native Americans, set about creating an Anglo-American nation state. Their America would have been politically different from the old countries of Europe with their monarchs and aristocrats, but it would not have been ethnically different. It would have been a constitutional republic of English speakers, mostly from England and Scotland and mostly Protestant—a WASP republic, with an African population enslaved and barred from citizenship. And then, in the course of the 19th century, these settlers, with considerable reluctance and sporadic resistance, allowed themselves to become a minority in what they thought was their country.How did this happen? First of all, the settlement was relatively recent. America was the ancient homeland of the Indians, but not of anyone else; the cruelty of their displacement left only a society of immigrants. And, second, the settlers needed more settlers, more workers for a steadily expanding economy. Most historians will tell you that this need was the major reason for America’s open borders, and that is almost certainly true. But the need for workers explains only the open borders; it doesn’t explain, and didn’t necessarily lead to, a republic open to new citizens. The strongest defenders of a WASP nation-state didn’t object so much to immigration; they were focused on naturalization. One of the key proposals of the Know Nothing Party of the 1840s and ’50s was for a 25-year span between residence and citizenship. In 25 years, maybe, all those Irish Catholic immigrants, or their children, would become good Americans.In fact, the Irish began to vote long before that; German ’48ers were almost immediately politically engaged; Mexicans became American citizens thanks to the war with Mexico and the conquest of the far West; after the Civil War, Black Americans were entitled (and in a few places actually allowed) to vote; and then, though Asian immigrants were barred, hordes of Italians, Jews, Poles, Slovaks, and many others arrived, and the WASPs were suddenly a minority not only among the inhabitants of the country but also among the citizens of the republic. Birthright citizenship made this process faster than it might otherwise have been, but the outcome, I think, was inevitable. Today white nationalists, like the WASP nationalists of the 19th century, worry that they are on the way to minority status. And they are probably right.These transformations are what make America different. No one expects anything similar to happen in the old countries of Europe (or in Asian countries like Japan). The Danes, for example, won’t allow themselves to become a minority in their own country. If that was ever a likely prospect, or even a distant but possible prospect, no one would blame them for taking measures to prevent it from happening. Well, “no one” is probably an exaggeration; advocates of open borders would castigate them as backward nativists. But let’s imagine a not entirely weird scenario: Millions of climate refugees are struggling to reach Europe. All the countries of the continent build (physical and legal) walls to keep them out—except Denmark, which holds a referendum on a proposal to take in large numbers but to stop well short of making the Danes a minority. There are two other options on the ballot: Voters can also choose to build the walls that everyone else is building, or to open the borders. Imagine yourself a Dane—not a philosopher thinking abstractly about everyone in the world, but an actual Dane—how would you vote?Recently, a Polish nationalist politician argued against letting in a couple of thousand Syrians because, he said, he didn’t want the Poles to become a minority in Poland. So that’s the nasty version, and also the dishonest version (there are 38 million Poles), of the argument I just made but haven’t yet defended.This is the argument: People have a right to be at home in their homeland, and this is a right that liberals and leftists should acknowledge. It’s not an absolute right; there are other rights of other people (strangers) that may come into conflict with this one and require a politics of balance and compromise. But this one is real: A people’s right to feel at home in the place where they live, where they have created a language, shared a history, shaped a landscape, established a calendar with holidays and ceremonies, participated (let’s say) in a democratic politics, contributed to a mutually beneficial welfare state. They have a right to hope that their grandchildren will grow up in that place, nourished by its traditions, protected by its institutions, engaged with their fellow citizens.The idea that they are members of an ongoing community is something that most people feel deeply—a community formed by the kind of contract that Edmund Burke described long ago: Among “the living, the dead, and those who are yet to be born.” Burke was a conservative writer, and I don’t often agree with him. But the conservation of communal life is a value that liberals and leftists (again) need to understand—and, with whatever qualifications, embrace. It is entirely compatible with a community that is open to outside political and cultural influence and to foreign immigrants. Indeed, all political communities evolve over time and enrich themselves by taking in and naturalizing new ideas and new people. This has been going on for centuries, and it doesn’t, it shouldn’t, interfere with the experience of continuity and belonging.The argument I have just made would permit countries like the old nation-states of Europe to set limits on the number of immigrants they take in, but only honest—and therefore distant—limits. The anti-immigrant nationalists currently ruling Poland and Hungary feed on and exploit the history and culture of their fellow nationals, but they are not the only or the best representatives of the nation. They have opponents who are no less committed to both the past and future of their people—and who are, at the same time, advocates of a more generous immigration policy. These liberal nationalists are faithful to the complexities of their countries’ history—to the ever-shifting borders and the ever-present minorities. But they also aim, and have a right to aim, at national continuity and at the production and reproduction of the national culture.Now, how does this argument apply to America, the exceptional country? What is the communal life, the history and culture, which we should aim to sustain over time? There are some people these days who imagine America as a nation-state, pretty much like all the others, indeed, not significantly different from Poland and Hungary—and who aim at a nationalist immigration policy. I have trouble recognizing the “nation” they describe, though it does have its representatives in our history such as the Know Nothing defenders of the WASP republic that I have already described, who lost out in the course of the 1840s and ’50s; the Southern racists and their Northern helpers who worked to restore white supremacy after Reconstruction; the pseudoscientific bigots of the early 20th century who proclaimed the intellectual and moral inferiority of Eastern and Southern Europeans (and of Blacks and Asians); and the all-Americans of the Red Scare and the Palmer Raids who finally managed to stop immigration in 1924 and for 41 years thereafter (which made the rescue of European Jewry in the 1930s impossible).Today, we are told, this kind of nationalism is represented by the white working class Americans who support Donald Trump. But consider the most obvious group of these Americans: the unemployed workers of the Rust Belt. They certainly don’t have a nationality of their own, different, say, from mine. Their grievances aren’t national grievances, and the long history of their struggle for the right to strike and organize isn’t a national history. Their unemployment today is overwhelmingly due to jobs being automated and to jobs leaving the country, not to foreigners arriving. Many of the Rust Belt workers were recently foreigners themselves. They have a lot to complain about; they are the victims of globalization, abandoned by the Democratic Party of Clinton and Obama. They are no longer protected by the strong unions that they created and can’t now sustain. But nationalist politicians can only exploit these complaints; they can’t appeal to a national culture because it isn’t there—and the restriction of immigration that they promise will bring no relief.The campaign for a white America is an especially nasty and dishonest nationalism, which I am ashamed to say is represented in the United States government today by a distant relative of mine, Stephen Miller, who doesn’t remember his grandparents. It is nasty because of the cruelties perpetrated in its name on our Southern border. It is dishonest because it misrepresents our history and culture; it fails to recognize what makes America different.The America of the new nationalists isn’t the exceptional America; it doesn’t follow from our past or point to our future; it doesn’t have a history that I can pass on to my children and grandchildren. It isn’t, I am sure, the America of most Tablet readers. Our America is, as Horace Kallen wrote, “a democracy of nationalities,” a society of immigrants gathered from many continents—the “huddled masses yearning to breathe free,” who came here and breathed free. We have a Burkean commitment to conserve that freedom and to extend it from old to new Americans.We do have a right, even an obligation, to “Americanize” the immigrants—which means, first of all, to assure them that they aren’t the first or the last new Americans; they are just part of the ongoing stream. Like earlier immigrants, we want them to learn the meaning of American citizenship so that they can join our political debates and, after five years, our electoral contests. We want them to become credal Americans, who know and honor the Declaration of Independence and the Constitution. They don’t have to become ethnic Americans, because there is no such thing.In the early 20th century, there were fierce debates about what Americanization entailed and whether it required coercion. It did require coercion but only in the form of compulsory education, with both public and private schools required to teach courses in American history and politics. And then, largely uncoerced, the immigrants became Americans—without becoming Protestants, without imitating Anglo-American customs, and often, in the first generation, without learning English. And today, they are becoming Americans without being white or becoming “white.”But how can people feel at home when immigrants from all over the world keep coming into their space? Well, “home” has many meanings. I feel most at home in a bustling American city full of men and women of different races and ethnicities, speaking different languages, pursuing happiness. I know that for some people difference inspires fear—a fear of loss and displacement that readily leads to resentment and anger. But difference is the American story; we’ve had a lot of time to get used to it. Even when the First World War and the restrictive legislation of 1924 cut off immigration, there was no letup in the pluralizing of America: Southern Blacks moved north in large numbers to cities like Detroit and Chicago. Already multiethnic, these cities now became multiracial.We all move around the country, carrying difference with us. In 1944, my parents, children in tow, moved from New York City to a small town in western Pennsylvania and bought a house. We were the first Jews on a block of old family Protestants. One next door neighbor never spoke to us, but the neighbors on the other side welcomed us and enthusiastically helped my mother plant what was called in those years a Victory Garden. They were at home with us, perhaps remembering their own immigrant ancestors, who may well have been fleeing religious persecution.If we are faithful to our own traditions, we will welcome immigrants like the desperate people marching north from Central America; we won’t build a wall; instead, we will reproduce the institutions of the Ellis Island that was—only better now and more humane, since we are a richer country. I am not arguing for the open borders favored by cosmopolitan leftists and libertarian rightists. I am willing to listen to arguments for setting limits on the number of immigrants in a given year—for reasons of political prudence or to prevent any weakening of our (radically incomplete) welfare state. But these are only cautionary arguments. The pull of our history and culture is in the other direction: Let them in! It is the patriotic thing to do.Who, in particular, should we let in? I am not concerned here with immigrants who come to America under some legally established quota system or who are recruited because of their skills, only with men and women who can plausibly argue that they should be taken in. And I assume that once they come in, they will be put on the path to citizenship. It seems obviously wrong to take people into a democratic state and then deny them all political rights. I can imagine an argument from capitalist managers, say, or right-wing politicians, that would go like this: We can bring in very large numbers of needed workers so long as we make them permanent guest workers, subordinated and exploitable. But I don’t take that to be a defensible position. So the claim of the outsiders is for full admission. What are the obligations of us insiders?The first group of people with a claim to come in are the relatives of American citizens. This group makes up a large number of recent legal immigrants, and it is potentially much larger. Given the mathematical work on “degrees of separation,” we can assume that family claims have no end. Each claimant has relatives of his or her own, who have relatives of their own, who have relatives, and so on. This is what is called, by its opponents, “chain migration,” and I assume that the government can set some limits on the chain—but not the narrow limits that President Trump wants to impose. Remember the old story of Joseph in Egypt, who brought in some 70 of his relatives, a goodly chain.Ethnic kinfolk make up the second group of claimants; their claim is particularly relevant to the nation-state and only peripherally to the United States (though Americans in trouble abroad should certainly be brought home). But I want to describe the claim of ethnic kin as a lead up to another group more important to us: ideological kinfolk. When the Soviet Union collapsed, the Finns brought in thousands of Russo-Finns who might have been in trouble in a Russian nation-state, and put them on a fast road to citizenship. This was, I suppose, a discriminatory act; there were probably a lot of other people who were going to be in trouble in the new Russia. But I think that the Finns were right to recognize a special obligation to their ethnic fellows. That might not be the end of their obligations, but it was a legitimate place to start. There are many other examples of this kind of discrimination: Greece taking in the Anatolian Greeks after the establishment of the modern Turkish state, for example; or West Germany taking in the East Prussian and Sudetenland Germans after World War II; or Israel taking in diaspora Jews fleeing anti-Semitism or seeking a Jewish homeland.But there also are obligations that cross ethnic lines. After the defeat of the 1848 revolutions, the Hungarian rebel leader Kossuth was enthusiastically welcomed to the United States, some of his fellow Hungarians settled here, and much larger numbers of German ’48ers came to New York and moved on, many of them to Ohio and Missouri. I was studying in England more than century later, in 1956, when London was suddenly full of Hungarians—another failed revolution. I assume some of the refugees made their way to New York. In the context of the cold war, these were friends of the Western democracies, and Britain and the United States were two of the leading democracies. Hence the obligation. But suppose the revolution had triumphed, the communist regime had been overthrown, and the refugees were former officials and members of the secret police. I doubt that Britain or the United States would have felt any obligation to take them in. The Soviet Union would have been obligated, assuming that the refugees wanted to go there. The United States is still a destination for men and women forced out of their own countries because they defended civil liberty and democratic politics. At the moment, though, they will probably have a hard time getting in.Men and women seeking political asylum make up the third group of people who claim a right to come in; they overlap with the ideological kin I’ve just described, but their range is wider. Their claim is based on the politics of their home country where they can no longer feel at home: If they remain there, they say, they will be imprisoned, tortured, or killed because of their political beliefs, their political activity, or their religion. The regime is brutal and they are dissidents, heretics, or infidels; or their country is in the midst of civil war, and they are on the wrong or the losing side. International law has established the right of such people to seek asylum and the right of states to grant it (and, very important, the right to refuse requests for extradition), but states have no legal obligation to grant asylum in any particular case. They have a right to investigate the claim and, perhaps, given the proliferation of brutal regimes in the world today, to set limits on the number of asylum seekers that they admit. But I would be inclined to argue that no state, and certainly not the United States, can rightly turn asylum seekers away—as so many Jews were turned away in the Nazi years. Remember the good ship St. Louis, whose desperate passengers were not allowed to disembark in Havana or New York.There are some asylum seekers that Americans undoubtedly have to take in: the ones who are fleeing brutal regimes that the U.S. government has promoted or funded. It would be better, of course, if our government only promoted and funded nonrepressive regimes. Different American policies in, say, Central America, might significantly reduce the number of asylum seekers struggling northward. For now, though, we must recognize the moral consequences of what we are actually doing—or what we have done.One more group of people require an American asylum: The men and women (and their families) who, in one way or another, collaborated with us in places like Vietnam, Afghanistan, and Iraq—or who, under American cover, came out as democrats, trade unionists, or feminists. These are people who will be at risk when we leave. In the case of Vietnam, they were at risk and were not taken along with American soldiers and diplomats in the hasty, ill-planned retreat from Saigon. Many of them were killed or sent to “reeducation” camps, but some (the “boat people”) escaped on their own, often in great danger, and were eventually brought to the United States. This is a case where generosity is obligatory, and we have not been generous; the number of Iraqis and Afghans granted asylum is astonishingly low, even though the killing of men and women identified as friends of the Americans has already begun.The last group of claimants are refugees. I follow the conventional distinction between people fleeing repression, who seek asylum, and people fleeing poverty or natural disaster, who seek refuge—these last are the refugees. In fact, there is again overlap between the two groups since brutal governments often rule over impoverished countries and civil wars bring destitution in their wake. In any case, the group of refugees is very large, and there is no country in the world that can be expected to take in all of them. This is a burden that has to be shared, and at the moment there is no agency capable of forcing reluctant countries to take in their share. The European Union tried to set quotas for its members, but many of them simply refused to accept the obligation—though the quotas were low, given the tide of refugees. Much larger quotas would still not come anywhere near the limit that I described earlier; they would not endanger the cultural coherence of EU states or reduce their material well-being or challenge the majority status of the natives.I should stop here and recognize the remarkable decision by the German government, led by Angela Merkel, to take in 1 million refugees in a single year, which should have set an example, but didn’t, for the rest of the EU—and also for the United States. But we should be ready for a much larger number. Surely our history is proof enough that if immigrants are welcomed and if naturalization is possible, they will become law-abiding, hardworking, and democratically engaged citizens.I haven’t yet addressed the hardest question: In the decades to come, if the scientists are right, we are going to see tens of millions of climate refugees fleeing what have become uninhabitable parts of our globe. Nobody is planning for those overwhelming numbers of desperate people. Where will they go? They will flee inland from rising waters; they will move in large numbers into neighboring countries, like the refugees from African wars and from the Syrian debacle. But they will also push north, into Europe, as so many have already done. And from Central America, they will march to the U.S. border in numbers that will dwarf the current migration.Without a plan, it is easy to predict what is going to happen here in the United States—and things won’t be different in other countries. Suddenly all of President Trump’s lies about the crisis at our southern border will seem true; xenophobia will have a more plausible object than ever before; and some future president will build the wall. I doubt that there will be many people arguing for open borders. What power will our own history and culture have then? I am sure that there will be acts of generosity, philanthropic organizations, efforts to reduce the suffering of the refugees. But we must also expect an opposite response.So, we need to address climate change right now. That is, no doubt, an insufficiently urgent sentence given the future I’ve just described. But unless there is a divine revelation repeating Isaiah’s message—“To share your bread with the hungry/And to take the wretched poor into your home”—a revelation that captures everyone’s mind and heart, we had better act now in mundane and practical ways, on a very large scale. We won’t do well when the flood comes.