Here’s What We Know About Trump’s Mexico Wall

Published: February 13, 2017 |  Last updated: March 29, 2017

President Donald Trump has directed the Department of Homeland Security to move forward with one of his more prominent campaign promises: to build a wall on the U.S. border with Mexico. But he hasn’t provided many details about the project, including when and how the wall would be built, or how much it would cost. Based on what we know so far, here are some answers about how his plan might work.

Estimates range from $8 billion to $40 billion, depending on whom you ask.

Trump estimates that the wall can be built for a figure ranging from $8 billion to $12 billion, and his first budget requests up to $2.6 billion in fiscal 2018 toward planning, designing and building it. Congressional Republicans said they expect it would cost from $12 billion to $15 billion, based on what it cost to build existing border fencing. According to Reuters, an internal Department of Homeland Security report said the wall could cost up to $21.6 billion.

Independent estimates have been much higher. A study published in the MIT Technology Review said a 1,000-mile wall would cost from $27 billion to $40 billion. The study estimated $8.7 billion for concrete, $4.6 billion for steel and labor costs at $14 billion to $27 billion. Separately, Bernstein Research calculated $15 billion to $25 billion for labor, land acquisition and construction costs.

Estimated Costs on Trump’s Wall Plan Vary Wildly
Trumps Wall With Mexico: How much would it cost to build Trump’s wall? Trumps Wall With Mexico: How much would it cost to build Trump’s wall?
Source: Bloomberg reporting

The border is almost 2,000 miles long, two-thirds of which tracks the Rio Grande River.

Land along the border cuts through cities, including San Ysidro, California, and El Paso, Texas, as well as rural farmland, desert, arroyos, craggy mountains and wildlife reserves. The border features an array of existing fencing, more than 30 border patrol stations and 25 legal ports of entry.

Trumps Wall With Mexico: What does the U.S.-Mexico border look like right now? Trumps Wall With Mexico: What does the U.S.-Mexico border look like right now?

Barriers span 653 miles of the U.S.-Mexico border, mostly along the western half.

Much of the southern borders of California, Arizona and New Mexico have existing barriers, ranging from 18-foot-tall iron fencing and corrugated metal to makeshift vehicle barriers and barbed wire.

Existing Barriers Along Southwest Border
Trumps Wall With Mexico: Where are border barriers already in place? Trumps Wall With Mexico: Where are border barriers already in place?
Sources: Center for Investigative Reporting, U.S. Customs and Border Protection

It’s hard to say. There were 408,870 border apprehensions in the southwest U.S. last year—a large number of which were people presenting themselves to border agents and seeking asylum.

That’s according to U.S. Border Patrol figures, and it also includes multiple figures for people who were caught multiple times. Apprehensions have declined to levels last seen in the early 1970s. It’s less clear how many successfully cross the border. Customs & Border Patrol tries to estimate the total based on surveillance footage, evidence of movement (e.g., footprints, overturned rocks, litter) and reports from local residents. In fiscal year 2015, Border Patrol claimed an 81 percent success rate in apprehending or turning back people who attempted to cross illegally.

Apprehensions Have Plummeted Since 2000
Trumps Wall With Mexico: How many people cross illegally into the U.S. from Mexico? Trumps Wall With Mexico: How many people cross illegally into the U.S. from Mexico?
Source: U.S. Customs and Border Protection

Outside estimates are less rosy. In a 2013 report, the Council on Foreign Relations estimated that Border Patrol’s success rate was in the 40 percent to 55 percent range. The Institute for Defense Analyses, a nonprofit, nonpartisan research group that works solely for U.S. government agencies, estimates that about 200,000 people made it across in 2015—down from an estimated 2 million entries in 2000.

Nearly half of all border apprehensions occur near the southernmost tip of Texas.

The area, known as the Rio Grande Valley Border Patrol Sector, accounted for 46 percent of all apprehensions in fiscal 2016. From 1998 to 2012, most apprehensions occurred near Tucson, Arizona. Much of Arizona’s southern border is now fenced off. That has significantly reduced crossings there but led to increased crossings further east, in Texas.

Apprehensions At U.S. Border Patrol Sectors in Fiscal 2016
Trumps Wall With Mexico: Where are people crossing illegally into the U.S.? Trumps Wall With Mexico: Where are people crossing illegally into the U.S.?
Source: U.S. Customs and Border Protection

Most of the existing border fence was built after 2006, under President George W. Bush.

Federally funded construction began in the 1990s, when 14 miles of fencing was built along the California border during the George H.W. Bush and Clinton administrations. The barriers targeted border crossers between Tijuana, Mexico, and San Diego.

In 2006, George W. Bush signed the Secure Fence Act, which ultimately led to construction of 653 miles of reinforced fencing along the U.S.-Mexico border. The Department of Homeland Security had finished most of the fencing by the time President Barack Obama took office in 2009, but the agency still has 47 miles of authorized, unfinished fencing to be constructed. Trump has cited the Secure Fence Act as the legal authority to restart the work on border barriers.

Trump’s Wall Would Expand on Existing Border Fencing
Trumps Wall With Mexico: Who put up the current border barriers? Trumps Wall With Mexico: Who put up the current border barriers?
Source: Department of Homeland Security

Trump has suggested a 1,000-mile-long physical barrier made of concrete, though the administration has also discussed other options.

In interviews, Trump has said precast concrete planks could be used to construct the wall, akin to border walls in Israel, and he has typically called for the wall to be around 40 feet tall. Since winning the election, he has said he'd be open to fencing along some stretches of the border, and that the wall would need to cover only half the 2,000-mile border, with natural barriers providing coverage of the rest. It's not clear how existing border barriers fit into this plan.

Department of Homeland Security Secretary John Kelly has characterized Trump's plan as consisting of “effective physical barriers, advanced technology and strategic deployment of law enforcement personnel.”

Polls suggest that most Americans don’t support building a border wall.

A poll conducted in August by Pew Research found that 61 percent of Americans are opposed to “building a wall along the entire border with Mexico,” while 36 percent favor it. Critics of the Pew survey have said Trump’s wall proposal doesn’t intend to cover the entire border.

A more recent Pew survey conducted in late November and early December asked respondents to prioritize eight possible proposals for U.S. immigration reform, and building a wall was the least popular option. Only 40 percent of respondents thought that building a border wall was a very important, or somewhat important, goal.

How Important is it to Build a Wall Along the U.S.-Mexico Border as a Goal for U.S. Immigration Policy?
Do Americans want to build a wall? Do Americans want to build a wall?
Source: Pew Research Center, survey conducted Nov. 29 - Dec. 12, 2016

Correction: This answer was updated on Feb. 13 to correct dates that the late 2016 Pew survey was conducted.

Construction can begin immediately, but Congress would need to approve most of the funding.

Shortly after taking office, Trump signed an executive order requiring the Department of Homeland Security to “immediately plan, design, and construct a physical wall along the southern border.” Trump’s team believes the Secure Fence Act of 2006 grants him permission to begin constructing a border wall, and he has directed the DHS to use already available federal funding to start the process. That law permits the DHS to “take all actions the secretary determines necessary and appropriate to achieve and maintain operational control over the entire international land and maritime borders of the United States.” It also included approval for “physical infrastructure enhancements,” such as the wall Trump has proposed.

According to Reuters, DHS has identified $20 million in existing funding that could go toward the project. But he would need billions of dollars in additional funds from Congress to complete it. House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell have publicly stated they support providing funding to build a wall. However, Democrats in the Senate are likely to complicate any efforts that would send a bill to President Trump.

The Secure Fence Act of 2006 Had Bipartisan Support
Trumps Wall With Mexico: Does a wall need Congressional approval? Trumps Wall With Mexico: Does a wall need Congressional approval?
Source: www.govtrack.us

It doesn’t appear that Mexico would directly pay for it, as Trump has insisted.

Mexican President Enrique Peña Nieto has been emphatic in refusing to fund Trump’s wall. This goes against Trump’s campaign promise that Mexico will pay for the project, but since winning the election, Trump has suggested that the U.S. can recoup wall expenses from Mexico via alternative methods.

Trumps Wall With Mexico: Would Mexico pay for a wall? Trumps Wall With Mexico: Would Mexico pay for a wall?

One possibility is that U.S. taxpayers would pay for it, and Congress would try to recoup the cost from Mexico.

Trump's first budget requests up to $2.6 billion in fiscal 2018 toward planning, designing and building a border wall, and an additional $314 million toward 500 new Border Patrol agents and 1,000 new Immigration and Customs Enforcement officers. Taxpayers would foot that bill if Congress approves the spending request.

And while the U.S. can’t legally force Mexico to pay for U.S. infrastructure, Trump and GOP leaders have suggested that there are other means of recouping construction costs from Mexico. In a January interview, House Speaker Ryan said: “We’re going to pay for it and front the money” and “There are a lot of different ways of getting Mexico to contribute to doing this.”

In April 2016, Trump said he could invoke the Patriot Act to cut off remittance payments to Mexico from Mexican immigrants living in the U.S. Mexicans sent home $25.7 billion in remittances in 2016, according to the Banco de Mexico. That's more than 95 percent of all remittances received by Mexico last year. Trump’s proposal would increase the requirements needed to wire money to a foreign nation, making it difficult for immigrants to send money home without documentation proving their legal status.

But Trump’s proposal has drawn skepticism from legal experts. A report from K&L Gates, an international law firm, said Trump’s plan raises constitutional questions and puts a significant burden on financial institutions. Stuart Anderson, the executive director of the National Foundation for American Policy, said Trump’s interpretation of the Patriot Act is too broad, and he anticipates that the proposal would be challenged in court.

More recently, White House Press Secretary Sean Spicer said that the U.S. could “easily pay for the wall” by imposing a 20 percent adjustment tax on Mexican exports to the U.S. However, Trump’s team later clarified that a border tax was just “one idea” that might work.

A “Buffet of Options”
Trumps Wall With Mexico: If Mexico doesn't pay for a wall, who would? Trumps Wall With Mexico: If Mexico doesn't pay for a wall, who would?
Source: Bloomberg reporting

Most likely, since previous border projects have also used eminent domain.

Two-thirds of the land along the border is private or state-owned. And most of that land is in Texas, where much of the border does not already have fencing. The Trump administration would probably need to use eminent domain to acquire the remaining land needed to complete a border wall.

The U.S. government has used eminent domain to acquire land for existing sections of the border fence, and legal precedent is on Trump’s side. In 2005, the Supreme Court ruled, in Kelo v. The City of New London, that local governments may force property owners to sell out and make way for private economic development when officials decide it would benefit the public.

Most Existing Barriers Were Built on Federal Land
Trumps Wall With Mexico: Would eminent domain be used to acquire land for a wall? Trumps Wall With Mexico: Would eminent domain be used to acquire land for a wall?
Sources: Center for Investigative Reporting, U.S. Customs and Border Protection, OpenStreetMap, Government Accountability Office, U.S. Department of the Interior, U.S. Geological Survey

Still, attempts to acquire land would certainly face challenges in court. Historically, wall-related land cases have taken years to resolve, with costly settlements often resulting. An Associated Press review of border-related eminent domain cases in 2012 found that the U.S. government spent approximately $15 million to acquire 300 properties along the border in Texas.

Some property owners, whose land would be caught between the wall and the Mexico border, are likely to file claims of lost property value, which could slow down any construction on a wall.

Homeland Security would probably solicit bids from private contractors for most of the work.

An executive order from President Trump instructed the Department of Homeland Security to plan, design and build the wall. But these types of projects are typically awarded to private contractors that undertake most of that work. For example, cement makers would be poised to gain from the project, especially those with production facilities along the border, such as Mexico’s CEMEX and Grupo Cementos de Chihuahua.

Estimates have ranged from the low thousands to tens of thousands.

Workers would be needed not just to assemble the wall itself but to bring supplies to the border; in some cases, they would even build roads to access remote areas where the wall would be located. However, finding workers for those jobs won’t be easy. Construction agencies in the area regularly struggle to find skilled laborers.

Several years, at best.

Securing funding for the entire project and acquiring land on which the wall would be built could cause significant delays. The bulk of the existing 653 miles of fencing took about three years to erect, but some of the more difficult terrain increased that timeline. Department of Homeland Security Secretary John Kelly has said the project will be “well under way within two years.” According to Reuters, an internal Department of Homeland Security report suggested the project could be finished by the end of 2020.

Border apprehensions tend to decrease in areas after barriers have been constructed, though other factors likely contribute.

There was a significant drop in apprehensions after fencing was built near San Diego in the early 1990s. The drop there was followed by a spike in apprehensions to the east, near Tucson, Arizona, where the border was less fortified. When fencing was extended across much of the Arizona border, apprehensions fell there, too. Now apprehensions are highest in the Rio Grande Valley Border Patrol Sector in southern Texas. Much of Texas lacks fencing, though there is some in the Rio Grande Valley.

Where People Are Apprehended Evolves Over Time
Trumps Wall With Mexico: Would a wall be effective Trumps Wall With Mexico: Would a wall be effective
Source: U.S. Customs and Border Protection

While fencing certainly contributed to fewer apprehensions at the U.S.-Mexico border, it is likely that several factors led to the drop. New border fencing often coincided with an increase in border patrol agents in the area. Apprehensions fell by half after the recession that ran from 2007 to 2009, when fewer economic opportunities in the U.S. may have deterred would-be migrants.

It's clear that reinforcement is not without limitations. Border agents told the New York Times that they found at least one tunnel a month from 2007 to 2010 as more fencing went up. Also, a wall wouldn't deter asylum seekers, who present themselves to border agents at legal ports of entry and currently make up a large number of those apprehended at the border. Nor would it stop immigrants who fly into the country and overstay legal visas. The Department of Homeland Security said almost 530,000 people overstayed in fiscal 2015, about 200,000 more than were apprehended at the border that same year.

In January, President Trump pointed to Israel's wall as a successful model, telling Fox News, “They were having a total disaster coming across, and they had a wall. It's 99.9 percent stoppage.”

A public rift between Trump and Peña Nieto could have larger implications for U.S.-Mexico trade.

Trump has insisted throughout his campaign and presidency that Mexico will pay for the wall. Peña Nieto has insisted his country will not, and he canceled his first visit to Trump’s White House after a Twitter standoff on the issue.

The tension has led to further talk of reworking or scrapping the North American Free Trade Agreement, a deal that currently allows $584 billion worth of goods to cross the borders tariff-free each year. Exports to the U.S. accounted for 26 percent of Mexico’s gross domestic product in 2015, according to data compiled by Bloomberg, and remittances from Mexicans living in the U.S. totaled an additional 2 percent that year. Disruption in trade and remittances could be painful for Mexico’s economy.

In light of the weakening relationship, Mexico has said it’s seeking to diversify trade, which could leave an opening for China to gain further influence in the region.

Trumps Wall With Mexico: How would a wall impact U.S.-Mexico relations? Trumps Wall With Mexico: How would a wall impact U.S.-Mexico relations?

Correction: This answer was updated on Feb. 13 to correct Mexican exports to the U.S. as a percentage of Mexico's GDP.