One of Trump’s biggest campaign promises was the simplistic idea that the United States would build a wall along the border with Mexico and that Mexico would pay for it.  The plan is simplistic in the fact that Trump and his supporters are generally ignorant of the difficulties involved in such an endeavor.  Nevertheless, the DHS issued a request in March for proposals to build such a wall that has received several responses from a variety of contractors.  In fact, about 100 vendors have submitted such proposals.

To understand the difficulties, it is perhaps best to look at the important Rio Grande valley.  Roughly half of the border with Mexico lies along the Rio Grande River and is located in Texas.  This area is an important region from a law enforcement standpoint also.  In one year, the US seized almost 327,000 pounds of smuggled marijuana, over 1,400 pounds of cocaine, and 187,000 illegal border crossings were apprehended.  Hence, this area would obviously be the top priority for any such wall.

Equally important is the fact that most of the land on the US side of the Rio Grande River is privately held and has been in private hands for generations.  Some deeds granted date back to Spanish rule of the region.  Since 2008, there are over 90 open lawsuits against the federal government from private land owners in this area.  In order to build a wall, the government must first obtain the land on which to build the wall.

Property owners have the support of Texas politicians- federal, state, and local- on both sides of the aisle.  Land ownership is sacrosanct in Texas.  Thus, the government’s attempts to “seize” private property for this venture could be politically damaging.  Opposing government efforts could tie things up for years in courts as both Bush and Obama found out.  And although the government has persuaded some landowners to give up land, there are over 300 condemnation orders pending.  To date, the government has spent $78 million obtaining land and fighting legal cases.

Most legal experts concede that Trump would have little trouble using eminent domain to get the land it needed since it is for national security purposes.  The question is whether he would and to what extent he would do so.  If one remembers from the campaign, Trump is an advocate of the use of eminent domain and has used it in the past in his business dealings.  Previous rounds of lawsuits have established lost property values as a result of eminent domain and any future “takings” will likely inflate the cost of land acquisitions.

The second aspect of his promise is that Mexico would pay for the wall.  That has since been walked back and he asserts that will occur “eventually.”  Trump asked Congress for a $2.6 billion down payment.  Trump estimates the eventual cost to be $12-15 billion, although the DHS estimates the cost at $21 billion.

One method and one suggested by Trump is to seize or tax immigrant remittances to Mexico whose value is estimated at $27 billion annually.  Trump suggested changing the Patriot Act to tap into some of that money should Mexico not pay up.  Most of that money goes to some of the poorest sections of Mexico according to Mexican banking authorities.  However, changing the Patriot Act would likely not receive any support from either party.

Taxing wire transfers has been suggested also, but that industry is opposed to such a tax.  Oklahoma places a tax on wire transfers that has raised $67 million since 2009.  Of course, that is only a tiny fraction of the eventual cost of a wall.  Since wire transfer companies do not ask for the immigration status of anyone, any tax would necessarily have to target all wire transfers which would affect those here legally and US citizens.  The optics of a new tax from an alleged tax-cutting president would be politically bad.

Another suggestion is using seized proceeds of drug smuggling cartels for use in building a wall.  The problem is that proceeds seized already occur and those seizures are remitted to the Treasury Department for specified purposes under existing laws.  Thus, Congress would have to change existing law which will likely not happen.  Another proposal is a tariff on Mexican exports to the US.  When the idea was “floated,” it drew swift opposition from Republicans and Democrats.  It would also damage relations with Mexico, likely lead to retaliatory actions by Mexico and increase consumer prices in the US.  Such an idea has very little support and way too many negatives.

The call for proposals from the DHS state that the wall be “aesthetically pleasing.”  The DHS will define that term (which is a scary thought).  California is a leader in opposition to the wall and has said they will use existing environmental laws to block construction.  Gubernatorial candidate Gavin Newsom has said he will use both federal and state environmental laws and regulations.

Newsom and other California officials are barking up the wrong tree.  First, state regulations have no effect on a federal construction project.  As for the federal laws, construction of a wall, fencing or barriers has already been approved under previous federal law which gives the DHS broad authority to waive environmental regulations.  For example, under the Secure Fence Act of 2006, national security concerns take priority over environmental concerns.

Under the REAL ID Act of 2005, the DHS has waived more than 30 federal environmental laws and regulations.  Another 19 laws were waived just for the San Pedro Riparian National Conservation Area.  Laws waived include the National Environmental Policy Act (NEPA), the Endangered Species Act, and others.  In 2008, the Supreme Court refused to entertain a challenge to the DHS waiving these laws.  Plaintiffs argued that the federal government was overstepping its constitutional powers.  It is doubtful that today’s Supreme Court would entertain a similar challenge from environmentalists.

From a technical standpoint, building a wall as envisioned by Trump is all but impossible.  The border is not some mythical line between two countries.  It is wetlands, flood plains, deserts, mountains, grassland and forests each creating a unique set of technological challenges.  For example, to maintain structural integrity, the wall would have to be anchored six feet underground in some areas and much deeper in other areas.  It cannot, under an existing treaty, obstruct the flow of the Colorado or Rio Grande Rivers or flood plains.  This would push construction of a wall up to three miles inside US territory in some places creating a sort of no-man’s land.

Given these reasons- technical, political, legal and fiscal- Trump’s signature campaign promise will never come to fruition as he and his supporters envisioned it, at least not during his presidency.  Instead, we should move onto more realistic solutions to solving illegal immigration across the southern border and that can start by encouraging populations to stay put where they are by improving the economies and problems in Central American countries thus decreasing the desire to come to the United States illegally in the first place.  Chances are that would be cheaper, more politically feasible and more lasting than a mythical wall.