Most of the immigration laws being implemented call for employers to make sure their employees are authorized to work in the United States. They require employers to check eligibility through a federal program known as E-Verify.
E-Verify operates through a database that compares an employer’s information from a worker’s Form I-9 to data from U.S Department of Homeland Security and Social Security Administration records.
After complaints by some in the business community about having to use E-Verify, some states are exempting employers with five or fewer employees, and allowing them to keep a copy of the new hire's driver's license instead of using the database.
In Alabama, all employers have to use E-Verify after April 1, but employers who do business with any government agency were required to use the system beginning Jan. 1.
Rosemary Elebash, state director of the National Federation of Independent Business, said many companies do business with government agencies, even if it's something small like catering a luncheon for a state college.
Alabama Gov. Robert Bentley said E-Verify is his favorite part of the immigration law because it provides employers a way to make sure employees are legal.
Many supporters of state-level efforts to enforce immigration laws say jobs are a magnet for undocumented immigrants, and striking at their ability to work is key to reducing the incentive to come of stay here illegally. They say that the federal government has not met its duty to control immigration, leaving states with little choice but to deal with the matter.
But many critics of such state laws have complained that enforcing immigration measures is a federal, not a state, duty.
In December, the U.S. Supreme Court said that it would hear arguments over whether Arizona was entitled to impose its anti-illegal immigration law.
In urging the court to hear the immigration case, Arizona argued that the Obama administration's contention that states "are powerless to use their own resources to enforce federal immigration standards without the express blessing of the federal executive goes to the heart of our nation's system of dual sovereignty and cooperative federalism."
In the meantime, several parts of various state immigration laws have been put on hold by federal judges pending the resolution of lawsuits by the U.S. Dept. of Justice. Provisions that have been blocked by the judges include such things as allowing police to check the immigration status of people they believe may be in the country illegally, provisions requiring schools to check the legal status of new students and making it a crime to transport an undocumented immigrant.
Not all new immigration laws are new punitive.
California has a measure that allows students who entered the country illegally to receive private financial aid at public colleges.
Bentley, a Republican, says he's working to clarify and simplify Alabama’s law -- considered the toughest state-level immigration in the nation -- which critics say has damaged the state's reputation internationally and caused hardships for legal residents.
Bentley said Alabama’s law, known as HB 56, has to eliminate unnecessary burdens on legal residents and businesses and protect faith-based services while ensuring that everyone working in Alabama is legal.
"We recognize that changes are needed to ensure that Alabama has not only the nation's most effective law, but one that is fair and just, promotes economic growth, preserves jobs for those in Alabama legally, and can be enforced effectively and without prejudice," the governor said.
This story contains material from The Associated Press.
Elizabeth Llorente can be reached firstname.lastname@example.org
Elizabeth Llorente is Senior Reporter for FoxNews.com, and can be reached at Elizabeth.Llorente@Foxnews.com. Follow her on Twitter @Liz_Llorente.