Donald Trump has promised to build a wall separating the United States from Mexico.

Its purpose: To stop the oncoming waves of illegal immigration from that country–and other poor, strife-torn nations in Central and Latin America.

Illegal aliens crossing into the United States

“Building a wall is easy, and it can be done inexpensively,” Trump said in an interview. “It’s not even a difficult project if you know what you’re doing.”

Skeptics have derided the sheer difficulties of building such a wall. Among these:

• The United States/Mexican border stretches for 1,954 miles–and encompasses rivers, deserts and mountains.
• Environmental and engineering problems.
• Squabbles with ranchers who don’t want to give up any of their land.
• Building such a wall would cost untold billions of dollars.
• Drug traffickers and smugglers could easily tunnel under it into the United States–as they are now doing.

But there is another way that, as President, Trump can attack illegal immigration: By attacking the “sanctuary cities” across the nation that illegally shield violators of Federal immigration laws from arrest. 

This would prove far cheaper and more effective than building a wall along the entire U.S.-Mexican border.

Among the 31 “sanctuary cities” of this country: Washington, D.C.; New York City; Los Angeles; Chicago; San Francisco; Santa Ana; San Diego; Salt Lake City; Phoenix; Dallas; Houston; Austin; Detroit; Jersey City; Minneapolis; Miami; Denver; Baltimore; Seattle; Portland, Oregon; New Haven, Connecticut; and Portland, Maine.

These cities have adopted “sanctuary” ordinances that forbid municipal funds or resources to be used to enforce federal immigration laws, usually by not allowing police or municipal employees to inquire about one’s immigration status.

All Trump has to do is cut off Federal funding to those cities which systematically defy the immigration laws of the United States.  

And on March 27, his attorney general, Jeff Sessions, threatened to do just that.  

“The Department of Justice will require that jurisdictions seeking or applying for DOJ grants to certify compliance with [U.S. Code 1373] as a condition of receiving those awards,” said Sessions in a surprise appearance at the White House Briefing Room. 

His reference was to a Federal law which says cities cannot prevent federal authorities from enforcing immigration laws.

“Block funding for sanctuary cities. We block the funding. No more funding,” Trump said in August, 2016, when he laid out his immigration plans at a rally in Phoenix. “Cities that refuse to cooperate with federal authorities will not receive taxpayer dollars.”

New York City, for example, could lose up to $10.4 billion in Federal funding. Its agencies that receive the biggest share of these monies: The Housing Authority, the Administration for Children’s Services and the Department of Social Services.

Mayors from “sanctuary cities” such as New York, Chicago, Baltimore and San Francisco have threatened to resist Trump’s threat.

Trump has never held public office, and there is much he has to learn about the difficulties of carrying out his programs. But his experience as a businessman has given him a solid feel for the power of greed and selfishness. And he knows well how to exploit both.

Donald Trump takes the oath of office

By blocking monies to “sanctuary cities,” Trump will quickly drive a wedge between ardent liberals such as Bill de Blazio and their constituents who depend on those infusions of Federal monies.

In New York, for example, once Federal monies are cut off:

• Legal American citizens won’t be able to obtain assistance for low- and moderate-income families to rent housing in the private market.
• American children needing care for their emotional or medical needs will be denied it.
• Americans wanting to adopt a foster care child will be unable to do so–because there won’t be monies to pay the officials who now staff these agencies.

In short: The beautiful “every-man-is-my-brother” theories of liberal politicians are about to slam head-on into the ugliness of real-world needs and wants.

And when legal citizens can’t obtain the government services they have been used to getting, they will quickly become enraged. 

At first, many–perhaps most–of the people living in “sanctuary cities” will rush to support their elected officials in refusing to knuckle under.

But as time passes, public needs will go unmet while Federal monies continue to be blocked. 

First they will aim their rage at the local–and elected–officials of these cities responsible for “sanctuary” policies. And then they will focus their anger on the illegal aliens being protected by civic officials.

This will be followed by increasing demands by legal–and law-abiding–American citizens for their elected officials to cooperate with Federal immigration agents.

As tensions rise, so will demands for the election of new mayors and supervisors. And the chief demand of those voters will be: “Turn over the illegal aliens and restore our public services!” 

Some citizens will almost certainly take out their anger on anyone who even looks Hispanic, let alone speaks only Spanish.

And those citizens who feel conscience-torn by demanding an end to “sanctuary cities” will console themselves with this literal truth: Illegal immigration is against the law–and local officials have a sworn duty to obey the law at all levels–including those laws they don’t agree with.