In 2012, many on the left welcomed a Supreme Court decision which prevented Arizona from punishing people for breaking federal immigration law.

Yet some of those same Democrats are seething now that the ruling is being used to defend President Donald Trump's deportation efforts. 

Case concerned Arizona law SB 1070

As Newsweek noted in an article published on Monday that the case in question was Arizona v. United States, which arose from a lawsuit filed by the Obama administration.

At issue was SB 1070, a controversial Arizona law which made being in violation of federal immigration statutes a state criminal offense.

White House lawyers argued that immigration enforcement is an exclusively federal matter and its authority therefore supersedes that of state and local officials.

"The Government of the United States has broad, undoubted power over the subject of immigration and the status of aliens," Justice Anthony Kennedy wrote in his majority opinion.

"The National Government has significant power to regulate immigration," he continued before adding, "With power comes responsibility, and the sound exercise of national power over immigration depends on the Nation's meeting its responsibility to base its laws on a political will informed by searching, thoughtful, rational civic discourse."

Trump administration cites Arizona to justify actions

Emma Winger serves as deputy legal director at the American Immigration Council, and she explained that the Arizona holding has since been used to strike block similar laws in Oklahoma and Texas.

"It has been interpreted, I have to say, remarkably consistently, by circuits from the Fifth Circuit to the Ninth Circuit, with some variations, to strike down or affirm district court decisions striking down state laws that have been viewed as attempts by the states to enforce immigration law," Winger told Newsweek.

"Arizona is really, primarily, about the limits on states in enforcing their own laws,"  the legal expert went on to point out.

"But it is true that the Trump administration has used Arizona and, to a greater degree, the supremacy clause which is the foundation of the Arizona decision, to argue that states and localities that do not participate in federal immigration enforcement are violating the supremacy clause," she acknowledged.

Stephen Miller: "America voted for mass deportations"

America voted for mass deportations. Violent insurrectionists, and the politicians who enable them, are trying to overthrow the results of the election.

— Stephen Miller (@StephenM) June 11, 2025

"America voted for mass deportations," Miller wrote in a social media post. "Violent insurrectionists, and the politicians who enable them, are trying to overthrow the results of the election."