By Susan Heavey
WASHINGTON (Reuters) - Democrats in the Senate are preparing a backup plan to thwart sweeping immigration laws in Arizona and other states if the nation's top court supports the hotly debated measures.
The U.S. Supreme Court on Wednesday will hear arguments in a case questioning an Arizona law that allows local police to check individuals' immigration status. The law, which was enacted in 2010 and is being copied in other states, has been criticized as promoting discrimination against minorities.
The Supreme Court's decision has important legal and political implications in an election year, when the reach of federal government, states rights and illegal immigration will be debated.
Democratic Senator Charles Schumer said on Tuesday if the high court upholds Arizona's law, he will introduce legislation that prevents state and local authorities from enforcing their own immigration rules.
"States like Arizona and Alabama will no longer be able to get away with saying they are simply 'helping the federal government' to enforce the law when they are really writing their own laws," Schumer said at a hearing held to highlight the issue one day before the court arguments begin.
Republicans were expected to counter with their own immigration reform legislation. While neither measure is expected to advance very far in Congress this year, they are likely to get a lot of attention in the run-up to November's presidential and congressional elections.
Republicans boycotted the hearing, dismissing it as political theater.
Arizona's measure allows police to check immigration status when a person is arrested or legally stopped, and some other states have gone farther. Proponents argue such efforts enforce federal immigration laws and help catch criminals.
But critics of the crackdown in the western state, which borders Mexico, say the law unfairly targets Latinos and encourages racial profiling based on the color of one's skin.
"If you have brown skin in my state, you're going to be asked to prove your citizenship," said Dennis DeConcini, a former Democratic U.S. senator from Arizona.
The Republican state senator who wrote the Arizona law, Russell Pearce, defended it as an effective tool to fight illegal immigration when federal agents do not. A Reuters/Ipsos poll shows most Americans generally support such laws.
"The invasion of illegal aliens we face today - convicted felons, drug cartels, gang members, human traffickers and even terrorists - pose one of the greatest threats to our nation," said Pearce, adding that his own son works as a sheriff and was shot by an illegal immigrant.
Others, including Arizona state legislator Steve Gallardo, a Democrat, pointed to law-abiding immigrants who now feel compelled to carry around their birth certificate or other documents in case they get pulled over.
"Its primary objective was to make second-class citizens of U.S. Latinos," said Gallardo, a fourth generation Mexican-American.
(Editing by Doina Chiacu)