The Supreme Court has struck down key provisions of Arizona's crackdown on immigrants.

The court said Monday that one part of the law requiring police to check the status of someone they suspect is not in the United States legally could go forward. Even there, though, the justices said the provision could be subject to additional legal challenges.

Justices struck down three other key provisions of the law. One provision requires that all immigrants obtain or carry immigration registration papers. Another provision makes it a state criminal offense for an illegal immigrant to seek work or hold a job. The third provision struck down would have allowed police to arrest suspected illegal immigrants without warrants.

The ruling was unanimous in allowing the status check to go forward. But the court was divided on striking down the other provisions.

The Obama administration had sued to block the Arizona law soon after it was enacted two years ago.

Politicians are speaking out about the Supreme Court’s decisions on SB 1070.

Arizona Governor Jan Brewer has released a statement, claiming this ruling a victory for Arizona.

Governor Brewer said "today's decision by the U.S. Supreme court is a victory for the rule of law. It is also a victory for the 10th amendment and all Americans who believe in the inherent right and responsibility of states to defend their citizens. After more than two years of legal challenges, the heart of SB 1070 can now be implemented in accordance with the U.S. Constitution."

Meanwhile, the Senate's top Democrat said the Supreme Court's decision on Arizona's immigration law opens the way to racial profiling by police.

Senator Harry Reid said that the high court was right to strike down most of Arizona's immigration law, which President Barack Obama and many Democrats previously stated was unconstitutional.

However, Arizona Democrats said this ruling is “taking Arizona backwards.”

Arizona State Senator David Schapira says “The Supreme Court has sent two messages today: that states cannot pass policies that undermine federal law and that Congress must act on comprehensive reform in order to address this issue and avoid these kinds of legal conflicts. We cannot begin to honestly solve the issue of illegal immigration until those in Congress are willing to have meaningful discussions on comprehensive reform.”

Senators Jon Kyl and John McCain also made a joint statement, stating the law “was born out of the state’s frustration with the burdens that illegal immigration and continued drug smuggling impose on its schools, hospitals, criminal justice system and fragile desert environment, and an administration that chooses to set enforcement policies based on a political agenda … We will continue our efforts on behalf of the citizens of Arizona to secure our southern border."

The US Senate’s top Democrat also weighed in. Nevada Senator Harry Reid said he is concerned that the high court upheld one provision that requires police to check immigration papers of people they stop for other violations. That, Reid said predicted, "will lead to a system of racial profiling."

Homeland Security Secretary Janet Napolitano issued a statement, saying "The Court’s decision not to strike down Section Two at this time will make DHS’ work more challenging. Accordingly, DHS will implement operational enhancements to its programs in Arizona to ensure that the agency can remain focused on its priorities." Republican Presidential candidate Mitt Romney is also using the ruling as an opportunity to slam President Barack Obama’s immigration policy. Romney says the decision “underscores the need for a President who will lead on this critical issue and work in a bipartisan fashion to pursue a national immigration strategy.”

Five other states have adopted variations on the law. Parts of those were on hold pending the outcome of this case.