At last night’s Democratic debate, Elizabeth Warren stated, “A great nation does not separate children from their families.” It was a forceful rejoinder to many of the Trump administration’s immigration policies: separating more than 5,400 children from their families, sending families to Mexico to await the chance to make asylum claims and seeking the chance to detain children indefinitely. The administration has also supported efforts that would end “chain” migration and de-prioritize family reunification.

When discussing immigration, candidates like Warren are likely to gain support when they speak in support of keeping families together. Making family reunification the centerpiece of the legal immigration system strengthened the United States in the 20th century while increasing the migration of people of color and benefiting U.S. citizens who were able to bring family members to join them. Keeping families apart is an effort to reduce immigration and whiten America — and history suggests that despite attempts by nativists to brand family reunification with the derisive, dehumanizing term “chain” migration, the public will remain steadfastly supportive of keeping families together.

Around the turn of the 20th century, many families immigrated together to the United States. Between 1871 and the outbreak of World War I, 12.9 million immigrants came from Asia and Europe in search of economic opportunities, social mobility or safety. They joined millions of migrants around the globe who, at the end of the 19th century, left their countries to escape stagnant economies, political unrest or persecution to take advantage of the demand for unskilled labor in rapidly industrializing nations.

By 1920, the three largest groups of immigrants in the United States were Italians (4 million), Eastern European Jews (2 million, mostly from the Russian Empire) and Poles (1 million). These numbers stood in stark contrast to the years preceding the mass migration of the turn of the 20th century. Until the 1880s, 11,725 Italians and about 150,000 Jews, mostly of German descent, had entered the United States.