U.S. Sen. Mike Lee is pushing to end birthright citizenship in the United States after a Supreme Court ruling this week.

“We’re going to need a constitutional amendment,” the Utah Republican wrote Tuesday on social media after the decision came down.

“In today’s world, unrestricted, automatic birthright citizenship is suicidal,” he added. “The Supreme Court could and should have read the Fourteenth Amendment as something other than a suicide pact. Those who drafted and ratified that provision certainly didn’t regard it as such.”

In the days since, Lee has posted about restricting birthright citizenship nearly a dozen times, often linking the ruling to his SAVE America Act, which would require people to provide evidence of citizenship when registering to vote.

Lee did not respond to a Salt Lake Tribune request for further comment.

Birthright citizenship is a right guaranteed in the Constitution’s 14th Amendment, which reads in part, “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”

On Tuesday, the justices, in a 6-3 vote, struck down President Donald Trump’s executive order limiting birthright citizenship. Trump has wanted to prevent babies born to immigrants lacking permanent legal status from automatically becoming Americans.

“The framers of the 14th Amendment extended that promise [of citizenship] to ‘every free-born person in this land,” Chief Justice John Roberts wrote. “We keep that promise today.”

Lee has historically identified as a staunch constitutional originalist, meaning he believes the document should be interpreted based on the meaning at the time it was written.

On his official X account, Lee argued that the court’s birthright citizenship ruling went against the founders’ intentions.

“Neither the Founding Fathers, nor the authors of the 14th Amendment, nor the millions of Americans who fought and died for their country through the ages intended to establish a nation whose citizenship could so easily be purchased, whether through birth tourism of China’s communist party members or a vast border invasion enabled by faithless presidents,” he wrote, before advocating again for a constitutional amendment.

Lee suggested Congress pass a bill to limit the definition of “subject to the jurisdiction thereof.” He has also argued repeatedly for restricting birthright citizenship in U.S. territories.

“At a minimum, it’s time to limit birthright citizenship as to U.S. territories,” he wrote on X. “President Trump should instruct @SecMullinDHS to reverse the existing DHS policy allowing Chinese nationals to enter the Northern Mariana Islands — a U.S. territory — for up to 14 days without a visa.”