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(CNN) -- The United States is walking a path to greater diversity. And younger people are leading the way.

For the first time in national history, the majority of young people in two states -- California and New Mexico -- now identify as Hispanic, according to census data released this year.

In eight additional states -- Nevada, Arizona, Texas, Mississippi, Georgia, Florida, Maryland and Hawaii -- white children are in the minority compared with peers from other racial and ethnic groups combined, according to data analyzed by William Frey at the Brookings Institution.

The number of white children in the United States actually shrank by 4.3 million kids from 2000 to 2010, according to the analysis.

Meanwhile, the number of Hispanic and Asian children grew by a total of 5.5 million. Hispanics made up the bulk of this growth.

"Were it not for Hispanics, the nation's child population would have declined," Frey writes in his report, titled "America's Diverse Future."

The trend is expected to continue, with changes first hitting people younger than 18, then spreading as generations age.

The U.S. Census Bureau, which has been releasing data about the makeup of the nation following its 2010 count, estimates America's young people will become "minority white" in 2023.

About two decades later, in 2042, the same will be true for adults.

Some demographers, including Frey, expect those milestones to occur even sooner than that.

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Americans may be surprised by these shifts, but in California and New Mexico, issues of increasing diversity are kind of old hat, demographers and residents said in interviews.

There are at least two reasons for this.

For one, young people are generally more open to diversity; it's so much the norm, they hardly notice it.

"I don't have friends from different ethnic groups," said Isaac Gonzalez, a 15-year-old in San Bernardino, California. "I just have friends who like baseball and friends who go to school and friends who I hang out with."

And another reason: The Hispanic growth in California and New Mexico is nothing new. It started around the mid-1960s and has actually leveled off in recent years.

"The one thing you can say about California is everyone here eats tacos," said Dowell Myers, a professor of urban planning and demographer at the University of Southern California.

Immigration is "not the rocket ship it used to be" there, he said.

The state is settling into a new normal.

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Meanwhile, in places such as Arizona, Colorado, Georgia and South Carolina, these changes are creating more tensions, in part, demographers say, because change is happening at such a fast clip.

South Carolina's Hispanic population increased 148% between 2000 and 2010, faster than any other state during that period, census data show.

California's Hispanic population increased only by 28%.

All of these changes have policy and social implications.

"The accelerating growth of new minority children heralds an increasingly diverse future child population and labor force, presenting challenges for America's social and political systems," Frey, from Brookings, writes.

What older white generations need to realize is that they're in a partnership with the country's increasingly Hispanic younger people, said Myers, the USC professor.

It's in everyone's interest that these diverse young people succeed, he said, because they will serve as a backbone of the national economy and will support social programs older Americans rely upon, such as Social Security.

But Hispanic kids currently lag behind their peers in terms of high school graduation rates and college acceptance.

More than 17% of Hispanic people ages 16 to 24 are high-school dropouts; compared with only 6% of whites, 9% of blacks and 4% of Asians of the same age group, according to 2009 data analyzed by the Pew Hispanic Center.

"Many of them value a college education and their parents put an emphasis on college education and getting more schooling," said Mark Hugo Lopez, associate director of that center, "but in some respects they're unable to, based on resources."

English proficiency, which is a concern both for success in school and also in the job market, is less of an issue for the younger Hispanic population than for older Hispanic people, Frey said.

"What we know when we look at the numbers for young people is they speak English in school, they speak English with their friends but when they come home, they speak Spanish with their parents," he said. "Many of their parents aren't as proficient in English as they are."

Daniel Rayon, 13, who was born in Mexico, said his mom is unemployed and can't find work because she doesn't speak English. "It makes me mad sometimes because I'm telling her things and she can't understand," he said.

Many Hispanic kids don't speak Spanish.

Vincent Salinas, 16, who speaks only English, said most of his friends' parents speak Spanish, which means he doesn't really know them.

"It makes me feel sad," he said, "like I'm supposed to speak Spanish."

A greater percentage of young Hispanics were born in the United States than their older counterparts, which may explain the language gap.

About two-thirds of young Latinos were born in the U.S., according to the Pew.

Overall, this may sound like a lot of change for America. Taken loosely, however, this trend also offers a history lesson.

Until the mid-1900s, the United States actually was a "melting pot" of ethnicities and cultures, said Frey, from Brookings. In 1910, for example, nearly 15% of people in the U.S. were born in another country.

By 1970, that number dropped below 5%. It's now back up above 12%, according to analysis of census data provided to CNN by Frey.

The national pendulum is swinging toward an era of more diversity.

"We're now getting back into our roots in a way," he said.