The two-year long fight over the controversial Arizona immigration law, SB 1070, finally came to an end on Monday, when the U.S. Supreme Court handed down its decision in Arizona v. United States. SB 1070, which permitted state officials to enforce federal immigration laws, made its way to the Supreme Court after the Ninth Circuit blocked portions of the bill last year. Three key provisions of the law were struck down on the grounds that they were preempted by federal immigration law, and one provision was upheld.

The first provision to be struck down was Section 3 of the bill, which made it a misdemeanor under state law for immigrants to fail to seek or carry federal registration papers. The Court held that the provision was preempted, as Congress intended registration of foreign nationals to be a “single integrated and all-embracing” federal system, leaving no room for states to regulate in the area.

The second provision appears in Section 5(C). Section 5(C) made it a crime in Arizona for immigrants to work or solicit work without employment authorization. The Court held that this provision was also preempted, as Congress had only imposed civil penalties on unlawful employment, specifically declining to impose criminal penalties.

The third provision struck down by the Supreme Court is Section 6, which gave local police the authority to make warrantless arrests of immigrants suspected of being removable. This provision would have provided state officers with greater arrest authority than federal immigration officers, and could be exercised with no instruction from the Federal Government. In writing the opinion of the Court, Justice Kennedy stated that Section 6 “violates the principle that the removal process is entrusted to the discretion of the Federal Government. …[It] creates an obstacle to the full purposes and objectives of Congress.”

Finally, section 2(B), one of the most controversial provisions, was upheld, as it was found to be too early to determine how the provision would be applied in practice. 2(B) requires local law enforcement to investigate into the immigration status of anyone stopped or arrested when “reasonable suspicion” exists that the person is in the U.S. unlawfully. This is the so-called “racial profiling” provision, as many believe the only way an officer could have “reasonable suspicion” that an immigrant is unlawfully present is through racial profiling. Even though the Court upheld the provision at 2(B), it nonetheless recognized these concerns, and thus left the door open for future challenges based on discrimination. Justice Kennedy stated that the Court’s holding “does not foreclose other preemption and constitutional challenges to the law as interpreted and applied after it goes into effect.”

Overall, the decision comes as both a victory and somewhat of a surprise to immigration community, as the Supreme Court Justices did not generally appear to be in favor of the law when oral arguments were heard in May. Nevertheless, the holding confirms what immigration advocates have argued all along— that immigration enforcement belongs to the Federal Government, and states are therefore prohibited from taking matters into their own hands.

For more information, please read the full text of the decision in Arizona v. United States.