Illustration by Ramon Padilla, USA TODAY

For 157 years, birthright citizenship has made anyone born in the United States a citizen – whether they are the child of citizens, foreign nationals living legally in the U.S. or unauthorized immigrants.

Earlier this year President Trump signed an executive order which seeks to restrict this right, which was established by the 14th Amendment in 1868. The Supreme Court heard arguments on Thursday (May 15) about the order, which would require at least one parent to be U.S. citizen or have permanent residency.

Changes to birthright laws would impact a large portion of the U.S. population. According to 2023 data from the U.S. Census, 22.8 million foreign-born, non-U.S. citizens live in the country.

How many people gain citizenship through birthright?

According to estimates from the Migration Policy Institute and Penn State’s Population Research Institute, ending birthright citizenship would result in an average of 255,000 children being born in the U.S. without citizenship each year, and would increase the amount of unauthorized migrants living in the U.S. by 2.7 million by 2045, and 5.4 million by 2075.

The Pew Research Center found in 2022 that about 4.4 million U.S.-born children under 18 live with an unauthorized immigrant parent.

How many unauthorized immigrants live in the U.S.

The number of unauthorized immigrants in the U.S. has increased from the 1990s, peaking at 12.2 million in 2007, according to estimates from the Pew Research Center:

Where does the foreign-born population live in the United States?

In 2022, nearly a quarter of the U.S. foreign-born population lived in California. Foreign-born populations made up more than 20% of New Jersey, New York, California and Florida's total population, according to the Census Bureau.

Foreign-born residents refers to anyone who was born outside of the U.S., including naturalized U.S. citizens, lawful permanent residents, temporary migrants, such as international students, humanitarian migrants such as refugees or asylees and unauthorized migrants.

In almost every state, the foreign-born population was larger in 2022 compared to 2010. Delaware,North Dakota, South Dakota and West Virginia experienced the largest increases of foreign-born populations between 2010 and 2022, with a bump of 40% or more in each state.

The foreign-born population in the U.S. has increased over the past five decades. In 1970, 4.7% of the U.S. population was born outside the U.S. By 2022, 13.9% of the U.S. population was foreign-born.

Where are foreign-born U.S. residents immigrating from?

More than half of foreign-born residents in the United States immigrated from countries in Latin America, according to the Census Bureau. Close to a third of residents immigrated from Asia.

What is naturalization?

The Council on Foreign Relations describes naturalization as a process where a non-U.S. citizen can apply for citizenship after meeting specific requirements, such as passing a civics test, demonstrating basic English proficiency and living in the States over a continuous period of time.

As of 2023, nearly 25 million of the foreign-born U.S. residents were naturalized citizens. The remainder include both lawful residents and unauthorized migrants.

Which countries grant birthright citizenship?

At least 35 nations provide birthright citizenship to anyone born within their borders, according to World Population Review map of birthright citizenship around the globe.

What's next?

The Trump administration on May 15 tried to convince the Supreme Court to let it broadly enforce the president’s new rules ending birthright citizenship for some, even though multiple lower courts have said his executive order is probably unconstitutional.

During arguments before the Supreme Court, several of the justices expressed concerns about the use of nationwide injunctions, but John Sauer, President Donald Trump’s solicitor general, faced pushback this week about whether limiting injunctions was appropriate in this case.

While the government said Trump’s policy should be in effect for anyone who doesn't try to challenge it, some justices questioned the practical effects of that patchwork scenario. And they suggested the administration avoided asking the Supreme Court to rule directly on the policy because they knew they would lose.

The justices are expected to rule by the end of June.

Read more:

Countries in the Americas grant birthright citizenship. What happens if they revoke it?

Key takeaways from the historic Supreme Court debate on birthright citizenship

Contributing: Lauren Villagran, Maureen Groppe, and Bart Jansen

This article originally appeared on USA TODAY: Trump wants to end birthright citizenship. How many people would that impact?

Reporting by Ramon Padilla and Sara Chernikoff, USA TODAY / USA TODAY

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