The nation's leading small-business organization backs an enforcement-first approach to immigration reform.

The National Federation of Independent Business endorsed legislation sponsored by Rep. Heath Shuler, D-N.C., that would beef up border security and require employers to use an electronic system to verify that their employees are eligible to work in the United States.

Other business groups contend that a guest-worker program must be included in immigration reform legislation. The NFIB also supports a guest-worker program, but "we understand the need to first secure our borders and verify employment status," said NFIB Executive Vice President Dan Danner.

Under the legislation, federal contractors and large employers would be required to use the government's now-voluntary E-Verify system, which checks a new employee's Social Security or visa numbers against government records, within a year. Businesses that employ between 100 and 250 workers would have two years before they would have to run new hires through E-Verify, while businesses with between 30 and 99 workers would have three years. Those with fewer than 30 employees would have four years before they would have to use E-Verify.