The Department of Homeland Security patrols the nation's borders, issues passports and deports illegal immigrants.
But the linchpin of future of immigration enforcement is stored in a secure facility in Woodlawn, where computer servers hold the digital Social Security records of hundreds of millions of Americans.
Since 1996, a growing number of employers have logged on to a password-protected Web site and queried those records to see whether job applicants are here legally.
The screening system, called Basic Pilot, is run by the Department of Homeland Security. But front-line workers in Social Security Administration offices across the country are doing much of the work needed to correct errors in the data and ensure that people are not unfairly denied jobs.
More than 17,000 employers have access to the database - a fraction of businesses nationwide. But from October 2005 to September of last year, those employers executed more than 1.7 million searches of Social Security data.
Those numbers are expected to grow. The now-imperiled Senate immigration proposal would require such a search, starting with new hires and, within three years, the rest of the work force, according to the Los Angeles Times, which reported on the Basic Pilot program in May.
Basic Pilot is a quick and easy way to enforce the nation's immigration laws. The search takes three to five seconds. Employers cull the information they use in the search from I-9 forms, which new hires are required to complete to prove their right to work and live here, according to the Times.
However, during a House Social Security subcommittee hearing on Basic Pilot last week, experts highlighted numerous problems with expanding the program.
First, the Social Security database contains errors. A recent report from the agency's inspector general found a 4.1 percent error rate. Not bad, the report concluded, especially because many of the errors are the result of people failing to report changes to the agency.
No matter whose fault it is, the error rate is still enough to generate an enormous amount of work for Social Security employees.
When job applicants are told they are here illegally - and they are here legally - they have to take time from work to visit an agency field office and prove their case. On average, every 100 queries generates three calls or visits to Social Security, according to congressional testimony from Frederick G. Streckewald, an assistant deputy SSA commissioner.
If the program is to expand, the agency will need more staff and, therefore, more money.
"As part of the process to correct our records, we need to verify" the person's identity, Streckewald said in testimony. "That is why virtually all of these changes are made during a face-to-face interview in our field offices."
The second problem is companies' misuse of the system. Employers are supposed to check records only on new hires, not current employees, and only after a person is extended a job offer.
But an investigation found flagrant abuses of the system. According to an inspector general's report in December, 21 of the 50 employers surveyed checked the database before extending an offer to someone and about 15 used the system to check on current employees.
Eight companies admitted that they would not hire people if the system had flagged their information, according to the report.
This is a problem because most workers who are flagged as being here illegally, called a "tentative nonconfirmation," are, in fact, authorized to work, according to testimony from Tyler Moran, employment policy director for the National Immigration Law Center.
"If the current flaws in the Basic Pilot are not addressed before it is made mandatory, it will lead to flawed implementation, frustration and even noncompliance, which will result in certain businesses and industries moving into the unregulated underground cash economy," Moran wrote.
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