More than 220 people from more than 40 countries are sworn in as naturalized U.S. citizens in Phoenix on July 4. (Carolyn Van Houten/The Washington Post)

President Trump has claimed that he’s preparing an executive order that would end the constitutional guarantee of birthright citizenship for babies born in the United States to noncitizens. If enacted, such an executive order will surely be met with legal challenges, and many experts are already questioning the constitutionality of the move.

How does the American public feel about the issue of birthright citizenship and potential efforts to amend the Constitution to eliminate the policy? Here are three key findings.

1. Public opinion depends on how you ask the question

As pollster Patrick Murray pointed out, public opinion on birthright citizenship — like on many issues — depends in part on how the question is asked. Americans seem more evenly divided on ending birthright citizenship for the children of “illegal” immigrants as opposed to “undocumented” or “unauthorized” immigrants. For example, a September 2015 CNN/ORC poll found that 49 percent opposed automatic citizenship for children born in the United States to parents who are in the country illegally, while 50 percent supported citizenship for these children.

But in an August 2015 MSNBC/Telemundo/Marist poll, only 31 percent said that the Constitution “should be changed so children of undocumented immigrants are not automatically granted citizenship,” while 62 percent said “we should continue to grant birthright citizenship to all children born in the U.S.”

In a more recent survey — the 2016 American National Election Study (ANES) — respondents were asked whether “the U.S. Constitution should be changed so that the children of unauthorized immigrants do not automatically get citizenship if they are born in this country.” In this survey, 30 percent favored this change, 41 percent opposed it, and 29 percent said they neither favored nor opposed it.

2. Republicans and Democrats’ opinions differ — but Republicans are more divided

Unsurprisingly, there are differences in how Democrats and Republicans feel about this issue. In the ANES, 45 percent of Republicans favored amending the Constitution to eliminate birthright citizenship, compared to only 20 percent of Democrats. A similar divide can be seen among Trump voters and those who supported Hillary Clinton.

However, this suggests no real consensus among Republicans: Over 25 percent opposed this proposal and 29 percent of Republicans did not favor or oppose it. Trump’s stance may therefore attract opposition within his own party — as, indeed, has already happened.

3. Ending birthright citizenship is particularly unpopular among Latinos, younger voters and those with college degrees

Views of birthright citizenship also depend on demography. According to the ANES, the proposal is not necessarily popular among any racial or ethnic group — only 34 percent of whites and 28 percent of blacks support it — but it is particularly unpopular among Latinos. Only 14 percent of Latinos support it while the majority, 62 percent, opposes it.

Similarly, opposition to ending birthright citizenship is more prevalent among those 40 years old and younger (46 percent) vs. those 41-60 (38 percent) or 61 and older (36 percent). These results are consistent with other generational differences in attitudes about immigrants.

Opposition is also more prevalent among those with a college degree (45 percent) than those without (38 percent). But among no group does a majority — or anything close to it — clearly support Trump’s proposal.

Ending birthright citizenship is more white identity politics

Many commentators have noted that Trump’s proposed executive order could be an effort to appeal to his base. But it is also an appeal to the politics of white identity. In my forthcoming book “White Identity Politics,” I show that white Americans who feel a sense of solidarity with their racial group and a sense of racial grievance are not only more likely to have voted for Trump in 2016 but also more likely to support eliminating birthright citizenship.

For example, 48 percent of whites who say their racial identity is extremely important to them would eliminate birthright citizenship, compared with 32 percent of the whites who do not identify with whites. This relationship persists even after accounting for racial prejudice, partisanship, education and other factors in a statistical model.

These results confirm what many commentators have suggested: Trump’s potential proposal to end birthright citizenship is perfectly consistent with an identity politics centered on white grievances.

Ashley Jardina is an assistant professor of political science at Duke University. Her book “White Identity Politics” is forthcoming from Cambridge University Press in 2019.