From immigration lawyer Matt Hayes:

In exchange for legal status for the group [the 1986 illegal alien amnesty --LW], Reagan insisted that the magnet attracting illegal aliens to the United States be removed by extinguishing any incentive for U.S. employers to hire illegal aliens. In tandem with the amnesty, Reagan campaigned for employer sanctions for hiring illegal aliens, sanctions so stringent that many at the time regarded them as draconian.

Reagan reasoned that if an employer were fined for hiring an illegal alien (as much as $1 million in the worst cases), any payroll savings achieved by the hiring would be wiped out by the fine. In effect, it would be more expensive to hire illegal aliens than to hire Americans or lawful permanent residents. The few illegal aliens who continued to take the gamble and cross the border would be intercepted by a robust and more generously funded Border Patrol.

While Reagan's 1986 immigration reforms can at least be called rational, they were a failure. Today, there are between 8 million and 11 million illegal aliens in the United States. The majority of them crossed our southern border and has found employment - illegal employment, but employment nonetheless. This is attributed to Sen. Ted Kennedy's eventual gutting of the enforcement mechanism for Reagan's employer sanctions, and successive administrations refusing to give our Border Patrol the resources it needs to achieve its mission...