"I don't think people fully appreciated what those laws had done," says Nancy Morawetz, referring to both IIRIRA and the other 1996 laws that affected immigration. In some ways, they're "still being sorted out today."
But one effect was clear: After IIRIRA, deportation from the United States went from a rare phenomenon to a relatively common one. "Before 1996, internal enforcement activities had not played a very significant role in immigration enforcement," sociologists Douglas Massey and Karen Pren have written. "Afterward, these activities rose to levels not seen since the deportation campaigns of the Great Depression."This particular law was passed during an era where Congress and the Clinton administration were both working to increase the amount of spending and agents on the US–Mexico border.
And after 9/11, the way the federal government handled immigration changed in two major ways. The bureaucracy was reorganized — and moved from the Department of Justice to the Department of Homeland Security. And the funding for immigration enforcement got put on steroids.
The combination of those gave rise to what Meissner and the Migration Policy Institute have called a "formidable machinery" for immigrant deportations — a machinery that took the US from deporting 70,000 immigrants in 1996 to 400,000 a year though the first term of the Obama administration. But that machine was built on the legal scaffolding of the options IIRIRA opened up.
"Both of those things have had so much more force because of this underlying statutory framework that they were able to tap into," says Meissner. In retrospect, "it was sort of a perfect storm."
But even though deportations exploded after the passage of IIRIRA, it didn't keep the population of unauthorized immigrants in the US from growing. It went from 5 million the year IIRIRA was passed to 12 million by 2006. (By contrast, during the decade between the Reagan "amnesty" and IIRIRA, the unauthorized population grew by only 2 million.)
These two things didn't happen despite each other. More immigration enforcement is one big reason why there are so many unauthorized immigrants in the US today.