In 1986, Congress passed a large immigration bill based on a simple deal: amnesty for settled illegal aliens in exchange for stricter enforcement of the law in the future, to minimize new illegal immigration.
The deal was not honored. The undocumented aliens got their amnesty, all right, but the promised future enforcement never materialized.
That's because once the amnesty was out of the way, there was no longer any political incentive to push for enforcement, and pressure from a wide variety of special-interest groups pushing for non-enforcement.
It is this history that stands in the way of today's drive for "comprehensive immigration reform."
Although no bill has yet been introduced, the outlines are the same as 25 years ago: legalization - read amnesty - for illegal immigrants in exchange for more promises to enforce the law.
But recent polls show that most Americans simply don't believe these latest promises from politicians. They understand what the president and many congressmen do not: If the law-enforcement tools to limit illegal immigration are not in place before an amnesty, we'll just end up with millions of new illegal immigrants within a few years.
That's why before even debating whether to give legal status to illegal immigrants, Congress and the administration need to take the steps necessary to ensure that any future amnesty won't just be a prelude to more amnesties in the future.
First, the borders. For all President Barack Obama's boasts, the border is not secure. Border arrests dropped significantly over the past few years, but that was largely due to the bad economy here and the good economy in Mexico.
Even at that lower level, border agents were arresting 1,000 illegal immigrants a day. And the flow has started rising again; in South Texas, arrests are double what they were two years ago.
That trend will continue unless we make the needed improvements - now, before any consideration of amnesty.
For example, the Border Patrol has doubled in size over the past decade, but it is still smaller than the New York Police Department, and has to keep an eye on 8,000 miles of borders.
Much of the 650 miles of border fencing is designed only to block cars and presents no obstacle to people on foot. What's more, the Department of Homeland Security acknowledged recently it has no real way of even measuring the security of the border.
But the border with Mexico is only one part of a functioning immigration-security system.
Close to half the illegal population entered on legitimate temporary visas - as tourists or students, for instance - and then just never left. Congress has mandated the development of a proper check-in/check-out system for foreign visitors, because we need to know who's checked out and returned home in order to know who's still here illegally.That sounds good until you realize that Congress did that in 1996, and has repeated the demand five more times since, and the system still isn't complete. What's more, Homeland Security Secretary Janet Napolitano has openly said she opposes implementing the required check-out part of such a system.
Finally, the most important change needed before talking about amnesty is to turn off the magnet of jobs.
A big step in that direction would be the universal use of an online tool for companies to check whether new hires are legal. Called E-Verify, this free, simple system is still only voluntary; until all employers have to use it to verify the routine hiring paperwork they already file, the ability to get a job will continue to draw people to settle here illegally.
Promises to enforce the border after an amnesty are meaningless. Those illegal immigrants who might truly warrant an amnesty are going to have to wait until politicians earn back the public's trust on the matter of immigration security.
Mark Krikorian is executive director of the Center for Immigration Studies. Readers can write him at CIS, 1629 K St. NW, Suite 600, Washington, D.C. 20006.