The controversial policy defers deportation for hundreds of thousands of people who came to the United States illegally as children, allowing them to get work permits and driver's licenses.
"This was an initiative that required a careful navigation between the potentially conflicting dictates of doing what is right, of doing what is lawful, of doing
what is doable, and of doing what is defensible, both in the court of law and, to a lesser degree, the court of public opinion," Napolitano told students at the University of Georgia Law School on Monday.
Napolitano confined her remarks to the past. She said she would not anticipate what President Obama plans to do next. But in his own words, Obama has said he intends to "fix as much of our immigration system" as he can, on his own.
He's widely expected to expand Napolitano's deferred deportation program to millions more illegal immigrants after the midterm election.
Napolitano on Monday explained how she helped "more than 675,000 young people, who were already in this country...come out from the shadows."
Categorically applying "deferred action" to that entire group of young people would have "raised serious questions," she admitted.
"It would run the risk of appearing to make law, and usurping Congress. Thus, it would be crucial, both legally and politically, to underscore that each case would be assessed individually, on its own merits -- similar, but not identical, to how a prosecutor decides to charge a case."
Napolitano said her solution was to require the so-called Dreamers to "step forward individually and apply for deferred status."
"At this point, I could not say with any degree of certainty that we would be able to pull off this approach," Napolitano told the students. "Individualized review of potentially hundreds of thousands of cases would require building complex new systems and processes within the existing bureaucracy – a daunting challenge.
"Who knew how it all would turn out? What I did know was that this was the right thing to do. What I believed was that it was lawful. And, while it would be a heavy lift, I expected it would be doable and, in the end, defensible."
Napolitano said she anticipated legal challenges to the new policy, and she got one from "a handful of immigration agents" who objected to DHS's policy of prosecutorial discretion, which prioritizes the removal of illegal aliens with criminal convictions.
"They argued, in effect, that DACA required them to break the law. How a law enforcement officer could confuse an effort that would enable them to focus their work on true bad actors -- as compared to Dreamers -- with a requirement that they break the law remains a mystery to me. Nonetheless, that was the position of some of our own agents."
Napolitano said she was "surprised" when a district court judge ruled that the case might have merit. But the judge also dismissed the case, ruling that it belonged in an administrative setting, not in federal court. That decision was appealed and is now pending before the Fifth Circuit Court of Appeals.
"Also predictable was the criticism that came from some corners of Congress. To hear our Congressional critics tell it, DACA was both an open invitation for young
people to illegally cross our borders, and a Constitutional power grab in the form of an executive amnesty program. It was neither," she insisted.
"Rather, DACA has managed -- in my admittedly less-than-objective view -- to hit the sweet spot in public service. DACA is no substitute for comprehensive immigration reform. This is why I have never stopped advocating for comprehensive immigration reform."
Four months ago, President Obama announced that he would take "aggressive steps" to "fix as much of our immigration system as I can, on my own, without Congress."
He directed his Homeland Security and Justice Departments to "identify additional actions my administration can take on our own, within my existing legal authorities, to do what Congress refuses to do and fix as much of our immigration system as we can."
In early September, President Obama repeated his intention to "find a way to encourage legal immigration and give people some path so that they can start paying taxes and pay a fine and learn English and be able to not look over their shoulder but be legal, since they’ve been living here for quite some time.”
Obama first promised to act before summer ended; but last month, he said he would issue his new orders some time after the midterm election, but before the end of the year.