The border between Mexico and the United States spans four states from California in the west to Texas in the east and is 1,989 miles long. It is the most frequently crossed border in the world with approximately 350 million legal crossings annually.
No one knows for sure how many illegal immigrants cross the Mexican border each year. In 2015, the Department of Homeland Security reported that it had apprehended 331,000 “illegal entrants” attempting to cross the southern border. It is assumed that about 40% of those trying to enter the country illegally are caught, which means that there were roughly 400,000 persons that illegally entered the U.S. in 2015.
Trump wants Mexico to pay $5-10 billion to build the wall
To secure the border, Donald Trump has proposed building a wall along the entire length of the U.S. - Mexico border. Trump has said that the wall would cost about $8 billion to build. Others have estimated that the cost would be double that.
The Mexican government and the Mexican people are totally against the idea of walling off the border.
— Andrés Rozental, former Mexican ambassador, and deputy foreign minister
Trump has proposed that Mexico should pay a one-time fee of $5-10 billion as its contribution to securing the border. Trump’s position is that Mexico receives approximately $24 billion a year in remittances from Mexican nationals living in the U.S., and it would be in Mexico’s national interest to make the contribution. If not, Trump has threatened to impose restrictions on the transfer of remittances. He also noted that Mexico needs access to U.S. markets and in 2015 the U.S. had a trade deficit with Mexico of $58 billion. Trump would raise tariffs to equalize the trade deficit if Mexico did not make its contribution. Trump also proposed increasing visa fees on the 350 million border crossings. A $10 increase would raise $3.5 billion a year. Mexico has said that they will not contribute towards the cost of the wall.
It's been done before: the Great Wall of China is 13,170 miles long
The concept of building a border wall is not new. The Great Wall of China was constructed over the course of 2000 years and stretches some 13,170 miles. While much of the Great Wall has disappeared over time, the last section of the Wall that was built during the Ming dynasty (1368-1644) can still be walked upon today.
However, the Chinese emperors did not have to deal with a Congress, courts, environmentalists, state legislators, and all the other interest groups that would oppose the fence and likely stretch out the construction time well into a second Trump term, assuming he’s elected in November.
Building the wall is technically feasible
Building the wall is technically feasible. Experts agree that the most efficient way would be to use pre-cast concrete panels. Each panel would need to be at least 20 feet high and be set at least five feet deep to discourage tunneling. The panels would each be ten to twenty feet long and reinforced with steel.
The challenge of Trump’s border wall is not technical, but logistical. Trump’s border wall, if built as he has described it, would be one of the largest civil works projects in the history of the country.
—Ali F. Rhuzkan
Nevertheless, if there was a national will to build a 2,000-mile long border wall it could be done. It would require an act of Congress to clear away many of the obstacles that could become points of failure, such as how to construct the wall along the Rio Grande without violating the National Environmental Policy Act, or the disruption of animal migration paths that might violate the Endangered Species Act. Congress could override most of these obstacles by declaring the wall a national security and public safety priority and appoint the Army Corps of Engineers to manage the project.
If Congress puts the language into a bill that says, ‘Go forth and execute,’ providing authorization and funding, then certainly, we as the Corps of Engineers would follow what’s in the law.
—Eugene Pawlik, spokesperson U.S. Army Corps of Engineers
There is already a 651-mile fence along the border
In 2006, President Bush signed the Secure Fence Act that called for constructing a secure fence along 700 miles of the U.S. Mexican border. The Act also doubled the budget for border security to $10.4 billion in 2007. To date, some 651 miles of the fence has been constructed.
The wall proposed by Trump would be higher and deeper than the existing fence and designed to be more effective. The final cost of construction would probably cost at least double the $8 billion estimated by Trump.
There are many issues surrounding Trump’s proposed wall that would likely require a national debate over immigration policy. However, should there be the national will to build the wall there are no insurmountable technical or logistical challenges that would prevent building the ‘Trump wall.’