New estimates from the Migration Policy Institute (MPI) and Penn State’s Population Research Institute reveal that repealing birthright citizenship for children born in the U.S. to unauthorized immigrants or certain noncitizens would not reduce unauthorized immigration, as proponents argue, but instead significantly increase the size of the unauthorized population—both now and in future generations.
The debate over birthright citizenship has resurfaced in recent months following an executive order signed in January by former President Donald Trump, which sought to end automatic citizenship for children born to certain noncitizens.
The order, currently blocked by federal courts pending constitutional review, would restrict birthright citizenship to children with at least one U.S. citizen or lawful permanent resident parent.
According to the MPI-Penn State projections, eliminating birthright citizenship for children born to unauthorized or temporary immigrant parents would add an estimated 2.7 million individuals to the unauthorized population by 2045 and 5.4 million by 2075.
Each year over the next half-century, approximately 255,000 babies born on U.S. soil would begin life without citizenship due to their parents’ immigration status.
These projections, based on conservative modeling, suggest that the policy change would not only expand the unauthorized population—currently estimated at 13.7 million—but also create a multigenerational underclass.
By 2075, an estimated 1.7 million U.S.-born individuals would lack citizenship or legal status despite having parents who were also born in the United States.
The long-term consequences could extend beyond immigration statistics, potentially undermining economic mobility and social cohesion as a growing number of U.S.-born residents live without the rights afforded to citizens.
The Supreme Court is set to hear arguments on the legality of the executive order on May 15, with the unusually expedited schedule underscoring the significance of the constitutional questions involved.
The court will determine whether the policy can be implemented nationally or in select states and whether state attorneys general have standing to challenge it.
Supporters of ending birthright citizenship, despite the US Constitution’s plain language on the matter, argue that it would deter unauthorized immigration.
However, the MPI-Penn State analysis indicates the opposite: withholding citizenship from children of noncitizen parents would increase the unauthorized population by 40% by 2075 compared to current projections.
Rather than shrinking the unauthorized population, the policy would leave millions more without legal status—including those born and raised on U.S. soil.
As legal and political battles continue, the study highlights the potential for lasting demographic and societal consequences if birthright citizenship is revoked. The findings suggest that such a change would not achieve its stated goals but instead deepen challenges surrounding immigration and integration for decades to come.