Because they harbor criminal aliens, sanctuary cities and the debate that surrounds them confound immigration law enforcement advocates. The dispute often centers on philosophical questions like how to define the term, and whether state and local governments have the authority to establish federal immigration policy. Local and state municipalities don’t have such power, and the Department of Justice can end the debate: order Immigration and Customs Enforcement agents into the offending jurisdictions with instructions to detain and begin removal proceedings against criminal aliens.

Attorney General Jeff Sessions has repeatedly railed against sanctuary cities, and threatened to withhold federal grant money from them. But sanctuary city mayors have rebuffed Sessions, often brazenly. Finally last week, in what appears an “enough is enough” statement, ICE and its Enforcement Removal Operations team launched “Operation Safe City.” The mission focused on cities and regions where ICE deportation officers are denied access to jails and prisons to interview suspected immigration violators and on jurisdictions that refuse to honor ICE detainers.

Those prioritized for removal included foreign nationals with criminal convictions or pending criminal charges, known gang members, immigration fugitives from justice who ignored final deportation orders, and those who feloniously re-entered the U.S. after deportation. Deferred action for childhood arrivals recipients (DACAs) were excluded from the ERO effort.

ICE arrested 498 aliens from 42 countries in these sanctuary cities: Baltimore, 28; Cook County, Illinois, 30; Denver, 63; Los Angeles, 101; New York, 45; Philadelphia, 107; Seattle, Wash., 33; Santa Clara County, Calif., 27; Washington, D.C., 14, and the state of Massachusetts, 50.

Among those arrested, and previously granted sanctuary by the rogue jurisdictions, were a Salvadoran woman living in Baltimore charged with murder and attempted murder, and convicted of first degree assault; an Indian national living in Boston and registered sex offender; and a Mexican living in San Jose who overstayed his visa for more than 10 years, and with previous felony convictions on drug charges and felony child cruelty with the possibility of injury or death. In each case, the aliens had been previously released from local jails before ICE could assume custody.

When the “Operation Safe City” results are compared to advocates’ absurd allegations that sanctuary cities are safer than non-sanctuaries, the claim’s foolishness becomes obvious. For example, in the most notorious sanctuary city, San Francisco, where in 2015 a five-time deported, seven-time convicted felon Juan Francisco Lopez-Sanchez murdered Kate Steinle, Mayor Ed Lee said earlier this year that he stands by his non-cooperation decision because “crime doesn’t know documentation.” Yet in San Francisco, “Operation Safe City” arrested a previously released Salvadoran alien with convictions for sex with a minor under the age of 16.

Across the political spectrum and with likely voters, sanctuary cites are overwhelmingly unpopular. Most Americans will support “Operation Safe City” for the obvious reason — criminal aliens endanger communities and should be removed.

Noting that non-cooperation undermines public safety, ICE Acting Director Thomas Homan said that shielding criminal aliens creates a magnet for more illegal immigrants, with criminals certain to be among them.

As long as sanctuary cities remain defiantly opposed to complying with federal immigration law, and refuse to protect the public, DOJ must continue its removal operations.

JOE GUZZARDI is a Californians for Population Stabilization Senior Writing Fellow. Contact him at joeguzzardi@capsweb.org and on Twitter @joeguzzardi19.