The Obama administration spent nearly $18 billion on immigration enforcement last year, significantly more than its spending on all the other major federal law enforcement agencies combined, says a new Migration Policy Institute study reported by the New York Times. Based on the vast resources devoted to monitoring foreigners coming into the U.S. and to detaining and deporting illegal immigrants, immigration control has become “the federal government’s highest criminal law enforcement priority,” the report concluded.

In recent years, the two main immigration enforcement agencies under the Department of Homeland Security have referred more cases to the courts for prosecution than all of the Justice Department’s law enforcement agencies combined, including the FBI, Drug Enforcement Administration, and the Bureau of Alcohol, Tobacco, Firearms and Explosives. Total spending on those agencies was $14 billion. The report was an opening salvo in a contentious debate over immigration that President Obama has pledged to lead. Its purpose was to show that the U.S. has built “a formidable enforcement machinery” since 1986, the last time Congress considered an overhaul of the immigration laws that included measures granting legal status to large numbers of illegal immigrants.