As Latino and other groups debate whether a planned citizenship question will dampen participation in the upcoming 2020 U.S. Census, several scholars argue the way the Census looks at race and ethnicity does not accurately reflect the way many Americans see themselves or others.

The latest Census projections say that America will shift to a majority-minority society in 2045, when the total number of whites falls below 50 percent. But experts like Richard Alba, a sociologist and professor at the City University of New York (CUNY), think this is a result of the way the Census divides America into two groups — white vs. nonwhite or majority vs. minority.

"A sizable and growing number of young people come from families with one white and one minority parent, as more adults form families across racial and ethnic lines. By far the largest group among them have Hispanic and white European ancestry," wrote Alba in a Washington Post analysis last February. "But you wouldn’t know that from the 2000 or 2010 Census results."

The children of mixed families, who have one white parent and one non-white, are counted as “not white” or a minority — meaning “Hispanic” or “Asian,” for example — even though one of their parents is white, according to Alba.

A more accurate picture of U.S. demographics should reflect not just whites or nonwhites, but a growing number of people who see themselves — or are seen by others — as living between both groups, experts argue.

“I think the way they (Census) projected the population exaggerates the degree of ethno-racial change because it fails to take into account the blending that’s ongoing for some parts of the Latino and Asian populations," Alba told NBC News.

Are Census classifications too fixed in time?

According to experts, people tend to think about race as a primary group which shares a set of inherited physical and cultural traits.

However, this idea becomes rigid over time. For people with mixed backgrounds, having to pick a race on the Census can be stressful, especially when the emphasis on inherited traits creates both physical and cultural boundaries that limit the scope of identity.

University of Florida sociologist Nicholas Vargas, an expert on Latino racial identity, says that though it may not be reflective of a large shift, there are subsets of immigrants who can move between racial boundaries and are seen by others as white.

But Vargas explains that if experts want to figure out whether racial dynamics are changing in the U.S., or whether the boundaries of whiteness are expanding to include other minorities, it is not only important to figure out how people self-identify but how they are seen by others.

In 2015, Vargas studied Latinos who identified as white. Interestingly, while 42 percent of Hispanic participants identified as white, only 6 percent reported being perceived as white by other Americans.

The way people see each other impacts how they identify racially. And experts say that the factor of belonging, and not belonging, to a group influences how they respond to the Census.

This was the case for 19 million Latinos who identified as “some other race” in the 2010 Census after being asked about their “origin and descent”.

The Bureau currently collects data about ethnicity (Hispanic, Latino or Spanish origin), but does not identify those ethnicities as a race like white, black, Asian, American Indian and Pacific Islander. For Latino respondents who did not identify with any of these groups, “some other race” became the only option.

Pew Research Center reported last year that identifying as Hispanic or Latino diminishes over generations so that only about 77 percent of the third generation — U.S. born children of U.S. born parents and immigrant grandparents — identifies as Hispanic or Latino. By the fourth generation, it's under half.

The share of Latinos who say they have a non-Latino parent or grandparent also increases over generations. About 18 percent of Latino immigrants do. By the third generation, the share rises to 65 percent, according to Pew.

Experts also say that the way people see themselves as belonging or not belonging to a racial group has impacted the way some Americans see themselves and their family generations later.

New York University professor James Fernández, an expert on Spanish immigration to the U.S., Cuba, and Puerto Rico, said that in the case of immigrant families from Spain, the stories told about them by later generations sometimes obscure the fact that they lived side by side with Cubans, Puerto Ricans and other Spanish speakers in the early 20th century.

“I get the sense, after interviewing some of the children and grandchildren of Spanish (from Spain) immigrants, that there is an anxiety to distinguish themselves from other Spanish speakers who are considered nonwhite,” said Fernández.

In the case of the first Mexican-Americans, even when the U.S. federal government considered them legally white — approximately 115,000 became naturalized U.S. citizens after the Mexican-American War in 1846-1848 — they were largely excluded from voting in eight southwestern states because mainstream Americans treated them as nonwhites.

For Laura E. Gómez, UCLA law professor and author of Manifest Destinies — a book that traces the origins of Mexican-Americans — this group’s identity is deeply connected with the history of the United States and reflects the racial attitudes of the country as it expanded borders and settled annexed territories.

Race was a category assigned by members of a dominant group, in this case, white Americans who won the Mexican-American War.

Today, Gómez said, Mexican-Americans are in a similar situation — how they see themselves is largely at odds with how some white Americans see them.

This tension between inner and outer perspectives is polarized even further by the two-question format on ethnicity and race — which was used in the 2010 Census and Latinos are expected to answer in the 2020 Census.

Under this format, the first question is, "Are you of Hispanic, Latino or Spanish origin?" and then the second question is "What is your race?" More than any other group, U.S. Hispanics answered: "some other race" in the 2010 Census.

“What sociologists talk about when they talk about ethnicity is something that is chosen,” Gómez told NBC News, “as opposed to race, which is something that is ascribed, or that other people assign to us in society. And this distinction between what is chosen and what is ascribed pushes the boundaries of identity.”

Now, as the government gears up for the 2020 Census, the national survey has to look beyond racial categories of being white and nonwhite — which reflects more the historic attitudes imposed by society on different groups than the mixed reality of modern-day America — and make it more inclusive to encourage greater participation and accuracy, Gómez said.

Experts said to achieve that, the 2020 Census should:

Count both citizens and non-citizens for the sake of enumeration

Take a wider perspective on the social and cultural experiences that shape individual identity

Change the categories of race to recognize groups like Latinos

Allow multiple choices to reflect mixed identities where respondents could pick being white for some purposes and nonwhite for others.

Despite a decade of research and testing of a new Latino identity question for the 2020 Census, the Trump administration announced in January it was sticking with the two-part 2010 question for Hispanics. It won't have a "Hispanic origin" category as one of the race options, which would have allowed people to also mark a second ethno-racial category like "white" and thus reflect more accurately how some Hispanics see themselves.

For scholars like Alba and Gómez, the 2020 Census won't paint a realistic picture of our demographics.

“The Census matters because it is the process that says who we are as a nation,” said Gómez. “Democracy is only as good as our numbers.”

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