Krikorian added that the policy is "essential for making sure that the border's taken seriously," adding, "This is a real law that you are violating."
Opponents argue that reason doesn't hold, because the pull to work is greater than the threat of prosecution.
The ACLU said the debate over the safety and security of American borders is coming at time when Southwest border apprehensions are at their lowest levels in four decades and net migration from Mexico is at zero.
The non-partisan group Pew Hispanic found in a 2012 survey that many factors contributed to the decline, including, "the weakened U.S. job and housing construction markets, heightened border enforcement, a rise in deportations, the growing dangers associated with illegal border crossings, the long-term decline in Mexico's birth rates and broader economic conditions in Mexico."
According to Heather Williams, first assistant federal public defender of Arizona, the financial cost of Operation Streamline is great.
"In fiscal year 2011, there were almost about 650,000 deportable immigrants arrested," she said. "If half of those were prosecuted through an Operation Streamline ... it would be at taxpayer cost of, minimum, $1.7 billion, and likely cost a lot more than that."
The cost to prosecute those crossing the border for work could be used, instead, the ACLU said, to prosecute those who are violent drug smugglers or other such threats to communities, not those who are just "trying to reunite with their families."
Krikorian, however, said the cost is relevant.
"This is something we should have been doing all along, and when you have to play catch-up to reassert authority in some place you abdicated it for so long ... this is one of the things that a national government has to do simply to maintain its own sovereignty," he said. "This is an essential function of the state."
According to U.S. Customs and Border Protection, Tucson, Ariz., had the most apprehensions of illegal immigrants, with an all-time high in 2000 of more than 600,000, Fiscal year 2011 saw the lowest numbers since 1971, with 123,285 apprehensions.
The Department of Homeland Security has also seen a steady decline in the number of arrests, with more than 1,043,863 in 2008 and 641,633 in 2011. Illegal reentry is the most prosecuted federal crime in the country.