Donald Trump’s unorthodox campaign has performed a public service by shining the national spotlight on the problem of “sanctuary cities” which shelter illegal aliens from deportation. The tragedy of Kate Steinle, who died in the arms of her father after being shot by an illegal alien, is that her death was preventable, yet officials have defiantly defended their sanctuary policies.

It wasn’t only the City and County of San Francisco that released the seven-times-convicted, five-times-deported Mexican who killed Kate Steinle; Obama’s ICE let him go, too. ICE has released many thousands of criminal aliens onto unsuspecting local communities instead of returning them to their countries of origin, including 121 who were subsequently charged with murdering Americans in the last five years.

According to government figures compiled by Jessica Vaughan, more than 8,100 deportable aliens (including 3,000 felons) were released by sanctuary cities and counties in just the first eight months of last year. Some 1,900 of those wrongly released aliens have already re-offended 4,300 more times, racking up 7,800 new charges including murder, violent assault, rape and child rape.

The first local sanctuary policy was officially adopted more than 30 years ago by Los Angeles’ notorious police chief, Daryl Gates. Since then, about 300 cities and counties have adopted one or more sanctuary policies, such as: refusing to inquire about immigration status when making a traffic stop or other routine police work; refusing to report a subject’s unlawful status to the appropriate federal agency (now called ICE); or refusing to honor a “detainer,” which is a written request to detain a subject until ICE can deport him.

Bills to stop local sanctuary policies were introduced in Congress and state legislatures, but they all wilted under pressure from amnesty advocates such as businesses dependent on cheap foreign labor. The U.S. House last week finally approved a bill to withhold certain federal reimbursements from sanctuaries, but the promise of a presidential veto assures that even this minor reform will never become law.

Headlines proclaim that Republicans voted to “crack down” on sanctuary cities, but nothing will change unless the restrictions are folded into a must-pass appropriations bill. Washington, D.C., for example, remains a sanctuary even though Congress has the constitutional power “to exercise exclusive legislation in all cases whatsoever” over our nation’s capital city.

Local sanctuary policies protect thousands from deportation, but the real damage is done at the federal level. Policies instituted by the administration of Barack Obama have effectively given sanctuary to millions, thanks to Obama’s wholesale refusal to enforce immigration laws.

Take Obama’s executive amnesty of last November 20, which would have given legal status and work permits (including Social Security numbers) to approximately 5 million of the estimated 11 million illegal aliens. A brave federal judge blocked the work permits, but the 5 million still benefit from Obama’s decision to give them a low enforcement priority, another form of sanctuary.

Obama recently extended lower-priority enforcement to several million more people, and approximately 87 percent of the illegal population – all but 1.4 million of the 11 million – are basically home free, as if the United States is now the sanctuary for the whole world.

Don’t assume that illegal immigration has stopped just because the official estimate of illegal population has remained steady at 11 to 12 million for a decade. To replace attrition (a.k.a. self-deportation), illegal immigration (which includes people who enter legally but don’t go home when their visas expire) continues unabated at the rate of 1,000 per day.

About 2.5 million people have entered illegally or become illegal since Obama took office on Jan. 20, 2009, and that number doesn’t even include legal immigration of over 1.1 million a year. The Census Bureau estimates that “net migration” will bring 14 million new immigrants to the United States during the next ten years.

Of all Obama’s sanctuary policies, probably the worst is his vast expansion of refugees and asylum policies. Largely unnoticed by national media, tens of thousands of so-called refugees, mostly from Muslim countries, are being resettled all over the United States.

The United States now receives more refugees than all other countries combined and plops them down in what are called “seed communities” where local opposition is not tolerated. There’s even a special federal program to combat “pockets of resistance” such as the recent uproar in Twin Falls, Idaho where the U.S. government wants to send 300 refugees from war-torn Syria.

The July 16 murders of four U.S. Marines and a U.S. Navy sailor in Chattanooga by a Kuwaiti-born Palestinian is a good example of the dangers of allowing Muslims to enter our country legally as refugees. Like the Boston Marathon bombing by the Tsarnaev brothers in 2013, and like the dozens of Somali young men who have disappeared from Minneapolis, Chattanooga is another case where children of immigrants are radicalized by the terrorist ideologies of the countries their parents came from.