It's the border barrier President Donald Trump promised in his campaign. It's the symbol of the ideas that many who oppose Trump have vowed to block.
But with a partial government shutdown looming, one thing remains far from settled: Is the border wall really being built?
The answer is entirely a matter of interpretation.
What's Trump's border wall progress?
Border barriers have been built under the Trump administration.
So far, those barriers are mostly replacements of other, existing fencing that was already in place — not new stretches of wall on any part of the border that was previously open.
And none of the new barriers use the designs that emerged from the construction of prototype "walls" in San Diego.
Funding for the barriers so far is limited to older designs, essentially the same fences as were built under previous administrations.
And all of these projects amount to a few miles of border barrier in total. A USA TODAY NETWORK project in 2017 examined the entire 2,000-mile border and showed most of it has no fence and no wall.
Helicopter footage of the full border shows most of it is open, and most of the barriers in Texas are built only in short spurts. At the same time, much of the unfenced border is remote, wild and distant from roads or construction supplies.
Apprehensions of border-crossers rose in the last year, but the numbers remain near the lowest levels in decades.
Is Trump's border wall the same as the border fence?
On the campaign trail, Trump often spoke of a "great wall," and usually invoked images of concrete. Even after he took office, he was clear that the border wall would be new and different from other fences, saying "We’re going to have a wall that works. We’re not going to have a wall like they have now, which is either nonexistent or a joke."
Since then, administration officials have made other statements. In April, Homeland Security Director Kirstjen Nielsen seemingly contradicted Trump's earlier statements about the wall, saying that new fences would be considered walls, even if those fences are being built to replace existing fences.
New border barriers are often described as "bollard walls," meaning the vertical steel bollards recognizable from much of the previous fence construction. And border officials have indeed announced these as new "walls."
THE WALL: Documentaries explore reality of the border.
Where is Trump's border wall being built?
If you consider the barrier projects "border walls," here are some of the locations:
- In April, the Border Patrol began construction of a "border wall" near El Paso at Santa Teresa, N.M. During a press conference, Aaron Hull, Chief Patrol Agent of the U.S. Border Patrol in El Paso sector, mostly referred to the project as the wall, sometimes calling it "fence" but quickly correcting himself. Hull said the metal barrier was the same design as others from the 2006 Secure Fence Act. The new barrier replaced existing metal posts which were designed only to block vehicles.
- In September, the Border Patrol announced construction of "a new 4-mile section of bollard wall" in the historic Chihuahuita neighborhood in El Paso. The new bollards replaced existing chain-link fencing.
- In October, border officials marked the completion of 2 miles of barriers near Calexico, Calif. Crews had replaced older metal fencing with new, 30-foot steel bollards, a project identified as a priority and funded under President Barack Obama.
- In November, Customs and Border Protection officials announced a contract for about 6 miles of "wall system" in the Rio Grande Valley. The project is supposed to include a concrete levee wall "to the height of the existing levee" with 18-foot bollards on top. That barrier is not being built yet; it's set to be started in February.
None of those barriers look like the wall prototypes built near San Diego, which Trump visited and praised earlier this year.
Homeland Security Secretary Kirstjen Nielsen tours border in Arizona
Is Mexico going to pay for the border wall?
So far, no.
Congress approved $1.6 billion this year for border security, which Trump has described as a “down payment” on his wall. That's U.S. tax dollars.
Not all of that $1.6 billion goes toward fences or walls.
The $1.6 billion is intended for general border security measures, which includes new technology along the border and repairs to existing barriers. Only $641 million was dedicated to building 33 miles of new barriers.
The bill that allocated that funding also contained a notable caveat: "The amounts ... shall only be available for operationally effective designs deployed as of the date of the Consolidated Appropriations Act, 2017 ...such as currently deployed steel bollard designs, that prioritize agent safety."
In other words: The funding can be used only for previous designs, not any new designs for Trump's border wall idea.
But the new designs might not be usable, anyway.
What's the status of the border wall prototypes?
U.S. Customs and Border Protection awarded eight contracts to six companies to build border-wall prototypes in 2017.
Four were made of reinforced concrete, and another four incorporated additional construction materials. Construction began on Sept. 26 on a strip of federally controlled land near San Diego.
Trump later visited the site, and remarked that he preferred a wall design that allowed Border Patrol agents to see through the barrier.
U.S. Customs and Border Protection did field tests on the 30-foot-tall structures. In August, the U.S. Government Accountability Office published a report about the results of that testing.
The tests revealed many of the prototypes, as built, failed to meet the same design standards that Customs and Border Protection had set out in its calls for submissions. The evaluations found that all four concrete prototypes had “extensive” construction challenges.
The GAO report did not disclose the cost-effectiveness of the eight prototypes.
President Donald Trump visits California on March 13, 2018
So is Trump's border wall being built or not?
Details aside, the administration has been consistent in saying any border security construction will be considered part of a "wall" or "wall system" under Trump.
"To us, it's all new wall," Nielsen said at a White House briefing in April. "If there was a wall before that needs to be replaced, it's being replaced by a new wall. This is Trump's border wall."
On Tuesday, Trump told Democratic leaders in a remarkable on-camera clash he would be "proud" to shut down the federal government if he doesn’t get the $5 billion he is demanding for the wall.
“If we don’t get what we want ... we will shut down the government," Trump said during an extraordinary public exchange with House Minority Leader Nancy Pelosi, D-Calif., and Senate Minority Leader Chuck Schumer, D-N.Y.
Pelosi and Schumer gave as good as they got, telling Trump he lacks the votes for border wall funding – even in the current Republican-controlled House – and is being irresponsible in threatening to halt the government over a project that would be ineffective at best.
"This has spiraled downward," Pelosi said at one point.
In the meeting, which featured finger-pointing, arm-waving and raised voices, Trump, Pelosi, and Schumer argued their positions.
Trump said his wall would stop criminals and drug dealers from entering the country; the Democrats said it wouldn't, and that Trump's demand for $5 billion is obstructing an agreement that already includes border security and will keep the government open when the current funding bill expires at midnight on Dec. 21.
Contributing: Alan Gomez and David Jackson, USA TODAY.