"We remain in a dangerous period where those appealing to anti-immigration elements are fueling a divisiveness and hostility that might take decades to overcome," Mr. Harrison said.
As a whole, the nation's minority population continues to rise, following a higher-than-expected Hispanic count in the 2010 census. Minorities increased 1.9 percent to 114.1 million, or 36.6 percent of the total US population, lifted by prior waves of immigration that brought in young families and boosted the number of Hispanic women in their prime childbearing years.
But a recent slowdown in the growth of the Hispanic and Asian populations is shifting notions on when the tipping point in U.S. diversity will come — the time when non-Hispanic whites become a minority. After 2010 census results suggested a crossover as early as 2040, demographers now believe the pivotal moment may be pushed back several years when new projections are released in December.
The annual growth rates for Hispanics and Asians fell sharply last year to just over 2 percent, roughly half the rates in 2000 and the lowest in more than a decade. The black growth rate stayed flat at 1 percent.
The immigrants staying put in the US for now include Narcisa Marcelino, 34, a single mother who lives with her two daughters, ages 10 and 5, in Martinsburg, W.Va. After crossing into the US from Mexico in 2000, she followed her brother to the eastern part of the state just outside the Baltimore-Washington region. The Martinsburg area is known for hiring hundreds of migrants annually to work in fruit orchards. Its Hispanic growth climbed from 14 percent to 18 percent between 2000 and 2005 before shrinking last year to 3.3 percent, still above the national average.