A Wall Street Journal columnist, Bret Stephens, has demonstrated the importance of a growing U.S. population and the need for immigration to sustain such growth.
“A decade ago, America’s fertility rate, at 2.12 children for every woman, was just above the replacement rate. That meant there could be modest population growth without immigration. But the fertility rate has since fallen: It’s now below replacement and at an all-time low.”
“Without immigration, our demographic destiny . . . [would leave] us with the worst of both worlds: economic stagnation without social stability. Multiethnic America would tear itself to pieces fighting over redistribution rights to the shrinking national pie.”
However, this “doesn’t have to be our fate. [I]immigrants aren’t a threat to American civilization. They are our civilization—bearers of a forward-looking notion of identity based on what people wish to become, not who they once were. Among those immigrants are 30% of all American Nobel Prize winners and the founders of 90 of our Fortune 500 companies—a figure that more than doubles when you include companies founded by the children of immigrants. If immigration means change, it forces dynamism. America is literally unimaginable without it.”
The importance of immigrants for U.S. vitality was an important conclusion of a recent study of 46 Midwestern metropolitan areas conducted by the Chicago Council on Global Affairs, a nonpartisan organization. In these metropolitan areas immigrants are helping offset population loss and economic strains caused by people moving away and by the retirements and deaths of native-born residents. In at least one of these metropolitan areas (Akron Ohio) immigrants and refugees were filling entry-level jobs for local manufacturing and food-processing companies that have had trouble hiring for those slots. This will become even more important in the future when many of the native-born workers will be retiring.
Another recent study concluded that international immigration is giving a boost to population growth in big urban areas in the U.S. even as local residents flee for places with lower housing costs. The top beneficiaries of international immigration were primarily major coastal cities, led by the Miami metropolitan area.
A more nuanced view of U.S. immigration is taken by Mark Krikorian, the Executive Director of Washington, D.C.’s Center for Immigration Studies, who would “limit immigration to the husbands, wives and young children of U.S. citizens; to skilled workers who rank among the top talents in the world; and to the small number of genuine refugees whose situation is so extraordinary that they cannot be helped where they are.” 
He claims that almost all of the arguments for limiting immigration share a common theme: protection. Even those advocating much more liberal immigration policies acknowledge the need to protect Americans from terrorists, foreign criminals and people who pose a threat to public health. Supporters of stricter limits, such as me, seek wider protections: protection for less-skilled workers, protection for the social safety net, and protection for the civic and cultural foundations of American society.”
Krikorian cites a study by the National Academies of Sciences, Engineering and Medicine finding that immigration boosts economic growth in the long term and modestly improves the country’s demographic profile as the native population ages while creating a small net economic benefit. But this net economic benefit involves a redistribution from labor to capital.
In contrast to the U.S., Bret Stephens points out, is Japan. Its birth rate is very low. Its life expectancy is very high. Its immigration is very low. As a result, Japan has an aging, declining population. “Japan’s population shrank by nearly a million between 2010 and 2015, the first absolute decline since census-taking began in the 1920s. On current trend the [current] population [of 127 million] will fall to 97 million by the middle of the century. Barely 10% of Japanese will be children. The rest of the population will divide almost evenly between working-age adults and the elderly.”
Moreover, as “Morgan Stanley’s Ruchir Sharma has noted, lousy demographics mean a lousy economy.. . . In 2016, Japan’s growth rate was 1%—and that was a relatively good year by recent standard. . . . The average rate of GDP growth in countries with shrinking working-age populations is only 1.5%.”
In short, Stephens concludes, “Americans may need reminding that the culture of openness about which conservatives so often complain is our abiding strength. Openness to different ideas, foreign goods and new people. And their babies . . . are also made in God’s image.”
 Another example is New York Times columnist, Nicholas Kristof, whose father, Wladyslaw Krzysztofowicz, was born in Romania (now Ukraine) and who came to the U.S. in 1952 with the sponsorship of a Presbyterian church in Portland, Oregon after he had been arrested by the Gestapo in World War II and imprisoned in a Yugoslav concentration camp after the war. (Kristof, Mr. Trump, Meet My Family, N.Y. Times (Jan. 2, 2017).
 Paral, Immigration a Demographic Lifeline in Midwestern Metros, Chicago Council on Global Affairs (Mar. 23, 2017); Connors, In the Midwest, Immigrants Are Stemming Population Decline, W.S.J. (Mar. 23, 2017).
 Kosisto, International Immigration Gives Boost to Big U.S. Cities, Study Says, W.S.J. (Mar. 23, 2017)
 Krikorian, The Real Immigration Debate: Who to Let In and Why, W.S.J. (Mar. 24, 2017) The Center for Immigration Studies asserts that it is “an independent, non-partisan, non-profit, research organization. Since our founding in 1985, we have pursued a single mission – providing immigration policymakers, the academic community, news media, and concerned citizens with reliable information about the social, economic, environmental, security, and fiscal consequences of legal and illegal immigration into the United States.”
 Therefore, Bret Stephens asserts that Iowa’s Congressman Stephen King was misguided and mistaken in his tweet about Dutch anti-Muslim politician Geert Wilders who called his country’s Moroccan population as “scum.” King said: “Wilders understands that culture and demographics are our destiny, We can’t restore our civilization with somebody else’s babies.”