Miriam Jordan of the Wall Street Journal has reported on the story:
The population of Latinos of Mexican origin, who represent nearly two-thirds of U.S. Hispanics, grew by 7.2 million between 2000 and 2010 as a result of births, but the Washington-based research center attributed only about 4.2 million to immigrant arrivals. In the previous two decades, the number of new Mexican immigrants in the U.S. either matched or exceeded the number of births.
The current surge in births follows the massive wave of Hispanic immigration to the U.S. that began in the 1970s. The tilt suggests that descendents of immigrants could be the main engine of U.S. population growth for decades to come.
Mr. Potter, the Texas state demographer, says the higher fertility among Hispanics is unlikely to last forever. "As the Hispanic population becomes more mainstream, fertility rates will decline," he said.
Some towns say Hispanics have helped them weather the economic downturn. But their arrival has also has posed challenges, such as pressure on schools to absorb new children.
"We just have to get through this transition time," says John R. Weeks, a demographer at San Diego State University. Ultimately, he says, "the children of immigrants are going to buoy up the economy. They are going to pay for Medicare and Social Security for the aging white population."