June 25 (Reuters) - A U.S. Supreme Court ruling on Monday upholding a key part of Arizona's crackdown on illegal immigrants may lend support to states where Republican-led legislatures have passed similar laws, insisting they had to act in a policy area in which the federal government has failed.

Here are some facts about the state laws and their status. 

ARIZONA 

The Arizona law, the first of several passed by Republican-led state legislatures to curb illegal immigrants, was signed by Governor Jan Brewer in April 2010 and has a provision requiring police to determine the immigration status of those they detain and suspect are in the country illegally. Brewer said the law was needed to safeguard Arizonans, whose state borders Mexico. This was the part the Supreme Court upheld on Monday.

Other parts of the Arizona law require immigrants to carry their papers at all times; ban illegal immigrants from soliciting work in public places; and allow police to arrest immigrants without a warrant if an officer believes they have committed a crime that would make them deportable. The Supreme Court ruled that these provisions went too far in intruding on federal law.

Parts of the Arizona law were blocked by a federal judge before it came into effect. Despite the Supreme Court ruling, a separate case will proceed challenging the Arizona law on grounds that it was unconstitutional and could lead to ethnic and racial profiling of the fast-growing Hispanic population.

ALABAMA 

Republican Governor Robert Bentley signed a law in June 2011, modeled on Arizona's law, requiring police to detain anyone suspected of being in the country illegally if the person cannot produce documentation when stopped for any reason.

The law, viewed as the toughest state immigration law in the country, also required public schools to determine students' immigration status, a provision that was temporarily blocked in October by a U.S. appeals court.

Immigration and civil rights activists urged the state to scale back some of the law's strictest provisions, but in May lawmakers approved a new bill with only minor changes and which included two provisions Bentley had initially questioned.

One was a new provision that the names of illegal immigrants be published if they appear in court on charges of violating state law whether they have been convicted or not.

The revised law also maintains a section from the original law that requires school systems to account for the immigration status of students unable to provide valid proof of residency.

GEORGIA 

A law signed by Republican Governor Nathan Deal in 2011 allows police to investigate the immigration status of those suspected of committing crimes, but that provision was temporarily blocked last June by a federal judge.

Another provision of the law which went into effect on Jan. 1 required many companies to enroll in the federal E-Verify program to determine whether their employees are eligible to work in the United States.

INDIANA 

A bill approved by Republican Governor Mitch Daniels in 2011 allows police to arrest anyone ordered deported by an immigration court.

That provision was blocked in June of last year by a federal judge who faulted it for not requiring the arrested person to be brought before a judge for potential release. Another provision of the law imposed E-Verify requirements on some employers.

SOUTH CAROLINA 

Republican Governor Nikki Haley signed a bill in 2011 that requires police to check the immigration status of those they detain, a provision that was blocked by a federal judge in December. The bill also barred illegal immigrants from soliciting or performing work in the state.

UTAH 

A two-pronged package of immigration laws signed by Republican Governor Gary Herbert in 2011 included an enforcement element modeled on Arizona's approach combined with a temporary guest-worker program.

Utah has been billed as having a softer and gentler approach to immigration than neighboring Arizona, partly because Utah's law is coupled with an existing provision allowing illegal immigrants to get driver privilege cards and partly because the law's language is less harsh. The Utah rules governing immigration checks, for example, give police discretion for people suspected in minor crimes.

The Utah law has been blocked by a federal judge pending the Arizona ruling and criticized by rights activists.

(Sources: Reuters; National Conference of State Legislatures and the University of California, San Diego, Center for Comparative Immigration Studies)

(Reporting By Alex Dobuzinskis)

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