The situation led to a few generations of resentful, displaced youths with only partial allegiance to the nation of their birth. Noncitizens born in Germany formed “parallel societies.” They were more prone to crime and political ideologies like radical Islamism or Kurdish nationalism. Their discontents have played out in German cities, most recently, in the form of Kurdish‐German attacks on Turkish‐German cultural centers.
The German Parliament took action to boost assimilation. In 1999, it extended citizenship to some children of non‐Germans born on or after January 1, 2000 and a handful of those born in the previous decade. According to a growing body of academic evidence, the positive effect was indisputable.
Immigrant parents of children newly covered by birthright citizenship gained more German friends, spoke more German, and read German newspapers more than others. They enrolled their children in preschool at a higher rate and started them earlier in primary school, which prompted a rise in German language proficiency and a decrease in social and emotional problems.
The fertility of immigrants with birthright‐citizen children fell, childhood obesity among them was reduced, and other health measures improved. Immigrants and their children, especially women, began to marry later and less often, in a pattern similar to Germans. These women were also more likely to marry men who were not from their own country of origin — another sign of good social integration.
The National Academies of Sciences’ recent report on studies of immigrant assimilation in the United States starts from the position that birthright citizenship is fundamental to the nation: It “is one of the most powerful mechanisms of formal political and civic inclusion in the United States.”
Unfortunately, Trump and his party largely disagree.
About 62% of Republicans think that immigrants today are less willing to adapt to American life than immigrants were a century ago, compared with just 17% of Democrats who hold that view. The last time a poll on the citizenship question was taken, in 2015, about half of Republicans wanted to amend the Constitution to repeal birthright citizenship — and the more conservative members of the tea party favored repeal by an almost 20‐point margin, 57% to 40%.
That makes conservative voices like those of Reihan Salam, author and National Review executive editor, all the more important. Salam favors birthright citizenship because otherwise we will be consumed by “the issues raised by creating a large class of stateless persons” born here without rights and no way to assimilate.
As University of Washington economist Jacob Vigdor summed up in his research on recent immigrants, fears of a lack of assimilation in the United States are overblown. “Basic indicators … from naturalization to English ability, are if anything stronger now than they were” in the Ellis Island era. The law guaranteeing birthright citizenship is part of the reason. Far from ridiculous, it guarantees that immigrants and their children are woven tightly into the American fabric. Let’s keep it in place, and the 14th Amendment intact.