Critics of the border wall proposed by President Trump have said the cost is prohibitive under current budget and economic conditions, that no way is Mexico going to pay for it, and shifting funds away from the TSA, Coast Guard, and FEMA are counterproductive in terms of national security.

These criticisms ignore the costs to the U.S. in terms other than money -- increased crime, overtaxed law enforcement, the drain on public resources such as education, medical care, etc., and the driving down of real wages through an endless supply of cheap labor.

In fact, thanks in large part to the mere threat of the wall, the sudden enforcement of existing law, and the stripping of funding from sanctuary cities by President Trump, illegal immigration has plummeted by 40 percent in February, a trend that if continued will reduce the costs and burdens of illegal immigration to the point that the benefits of enhanced border security, including the wall, will be more than paid for. As the New York Post noted:

The number of illegal immigrants crossing into the United States from Mexico declined by 40 percent from January to February, Homeland Security Secretary John Kelly said on Wednesday.

The downturn came after President Donald Trump took office on Jan. 20 vowing to deport many of the estimated 11 million illegal immigrants in the United States…

He said the U.S. Customs and Border Protection agency, which compiled the data, historically sees a 10 percent to 20 percent increase in apprehensions of illegal immigrants from January to February…

“Since the administration’s implementation of Executive Orders to enforce immigration laws, apprehensions and inadmissible activity is trending toward the lowest monthly total in at least the last five years,” Kelly said.

President Trump has shown that border security is not that hard. It merely requires willpower and resolve that puts the impact of illegal immigration on America and its citizens above the impact on the political fortunes of pandering politicians. Now comes a study from the Center for Immigration Studies showing that this ongoing reduction in illegal immigration will reduce related costs to the point the wall is paid for:

President Donald Trump’s border wall only needs to stop about 10 percent of illegal crossing in order to pay for itself, according to an analysis by the Center for Immigration Studies.The estimated $12 to $15 billion cost of the wall would quickly be offset by the savings to the government if fewer illegal immigrants arrive in the country over the next decade, CIS found. Only a small portion of the population of people who are expected to attempt an illegal crossing in the next decade -- between 9 and 12 percent -- would have to be stopped for the wall to totally pay for itself.

The analysis from CIS, a group that advocates for moderating immigration levels, relies on fiscal estimates from the National Academies of Sciences, Engineering and Medicine (NAS) for the average cost to taxpayers of illegal immigrants. NAS estimates one illegal immigrant costs state and local governments approximately $75,000 in a lifetime, taking into account taxes paid and the cost of providing benefits such as education and health care.

Critics say the costs of illegal immigration fall largely on state and local governments and it is a federal government burdened with debt that has to write the checks. But the costs in either case are born by the American taxpayer and the American worker. Ask Kate Steinle’s father what the true costs of illegal immigration are and who pays for them.

Trump was able to begin immediate construction of the border wall and opening up bidding for contracts thanks to a 2006 measure signed into law by President George W. Bush and supported by Democrats including then-senators Barack Obama, Joe Biden, and Hillary Clinton. 

Democrats are already grumbling about Donald Trump’s proposed border wall, though Barack Obama and other leaders in their party voted not so long ago for George W. Bush’s proposal to build a major wall on the border with Mexico.

Bush signed the proposal into law in 2006, after it was passed by huge bipartisan majorities in the House and Senate. The law ordered the Department of Homeland Security (DHS) to construct about 700 miles of fencing along the southern border, and authorized the addition of lights and cameras and sensors to enhance security. The law explicitly required the wall to be constructed of “at least two layers of reinforced fencing.”

Two-thirds of the Republican-led House approved the bill, including 64 Democrats, and 80 of 100 senators approved the bill in the Senate. Then Sens. Barack Obama, Joe Biden and Hillary Clinton were among the 26 Democrats who approved the bill. Supporters also included Sen. Chuck Schumer, who is set to take over leadership of the Senate for Democrats in 2016.

The Secure Fence Act of 2006 required the construction of 700 miles of new border fence along the 2,000-mile U.S.-Mexico border. “The Secretary of Homeland Security shall provide for at least two layers of reinforced fencing, the installation of additional physical barriers, roads, lighting, cameras and sensors…” the act said.

It was to be modeled on the success of the border barriers in the San Diego sector of the U.S. border. The operative word was “secure.” Instead of this two-layer secure fence what has been built consists of flimsy pedestrian fencing or vehicle fencing consisting of posts people can slither through.

The two-tier fence in San Diego runs 14 miles along the border with Tijuana, Mexico. The first layer is a high steel fence, with an inner high anti-climb fence with a no-man’s land in between. It has been amazingly effective. According to a 2005 report by the Congressional Research Service, illegal alien apprehensions in the San Diego sector dropped from 202,000 in 1992 to 9,000 in 2004.

Cameras and sensors played a part but the emphasis was on physical barriers and roads that were patrolled by real live border guards, not by robots. Then in 2006 the Democrats took back Congress and, in 2008, the White House.

They saw in unrestricted immigration a means to fundamentally transform the demographics of America and its political landscape. A wave of what some called “undocumented Democrats” would be allowed to flood across the border as ICE was told not to enforce the law. Former border state governor Janet Napolitano, who became DHS secretary, reportedly once said: “You show me a 50-foot fence and I’ll show you a 51-foot ladder at the border,” The rest, as they say, is history.

But the consequences of unrestricted illegal immigration soon became too big to ignore and with a candidate willing to touch the new third rail of American politics, border security, a political movement chanting “build the wall” swept Trump into power.

The San Diego fence worked. So will Trump’s wall. Build the Wall.   

Daniel John Sobieski is a freelance writer whose pieces have appeared in Investor’s Business Daily, Human Events, Reason Magazine and the Chicago Sun-Times among other publications.