President Donald Trump has described immigrants as “invading” the country and he has called American cities out of control. He has depicted both cities and immigrants as violent and infested.

There is a connection between immigrants and cities, though the two are not linked in the way Trump portrays them. Instead, as Emily Badger and Quoctrung Bui wrote recently in The New York Times, Trump’s “two oft-cited problems have historically been solutions to each other.”

Various studies show the benefits immigrants bring cities, from shoring up home values in sagging markets to spurring population growth where it had been falling to contributing to lower crime rates.

“There’s this symbiotic relationship that immigrants need cities in order to acclimate to a new society, and cities need new immigrants,” Jacob Vigdor, a professor of public policy at the University of Washington, told Badger and Bui.

The past 40 years illustrate how this symbiosis has worked. In “Barrio America,” historian A.K. Sandoval-Strausz argues that since the 1970s Hispanic immigration helped save many American cities at a time when white flight had taken hold and the Great Migration of African Americans from the South was winding down.

Domestic demographic trends left cities in need of people (and businesses, and tax revenue), just as new waves of Hispanic immigrants began to enter the country, Badger and Bui write. The new immigrants blunted or reversed population losses in Chicago, Milwaukee, Boston and elsewhere or contributed significantly if not entirely to the population booms in cities like Los Angeles and Houston.

This cycle of renewal is nothing new. As Badger and Bui report, urban neighborhoods and jobs have repeatedly been restocked as one group — the Irish, Italians, Chinese, Mexicans — moves in, prospers and moves away, to be replaced by newer arrivals.

But Trump’s immigration policies threaten this cycle. Is there a next wave to replace the recent immigrants when they also move up and out? The answer’s uncertain.

Read Badger and Bui’s complete story here.

The Immigrants Trump Denounces Help Revive the Cities He Scorns