Donald Trump travels to the border today, perhaps to declare a state of emergency but certainly to repeat the call for an impenetrable barrier along the frontier. A previously redacted report from the Department of Homeland Security suggests that they’re not having much success in finding such a model. According to NBC News, the report included photos of all eight prototype breached by Marines with ordinary household tools — including the “steel slats” fence.

This might be news if anyone thought it was possible to build a wall that couldn’t be breached under any circumstances:

President Donald Trump has repeatedly advocated for a steel slat design for his border wall, which he described as “absolutely critical to border security” in his Oval Office address to the nation Tuesday. But Department of Homeland Security testing of a steel slat prototype proved it could be cut through with a saw, according to a report by DHS.

A photo exclusively obtained by NBC News shows the results of the test after experts from the Marine Corps were instructed to attempt to destroy the barriers with common tools.

The Trump administration directed the construction of eight steel and concrete prototype walls that were built in Otay Mesa, California, just across the border from Tijuana, Mexico. Trump inspected the prototypes in March 2018. He has now settled on a steel slat, or steel bollard, design for the proposed border barrier additions. Steel bollard fencing has been used under previous administrations.

However, testing by DHS in late 2017 showed all eight prototypes, including the steel slats, were vulnerable to breaching, according to an internal February 2018 U.S. Customs and Border Protection report.

Earlier, the White House had bragged about the testing on these prototypes. At the time, the takeaway was that the prototypes were nearly impossible to scale, which is the priority for such barriers. However, it does matter to what extend such barriers can be made “impenetrable,” especially since Trump has made that an explicit promise.

On the other hand, that’s more of a theoretical issue, especially in this case. People crossing the border illegally don’t usually carry tools with them, not even “ordinary” tools. In fact, as ABC’s Matt Gutman reported this morning, they don’t carry anything at all — because the coyotes take it from them:

Gutman also notes that Customs and Border Protection (CBP) wants more of the steel slat fencing erected in the Rio Grande area. Based on this report, it’s not difficult to see why. People are getting dumped along this area because they can cross over easily on foot. Erecting barriers would allow CBP to secure the border more efficiently by narrowing the spaces in which foot traffic can occur, and likely would dry up the efforts to cross far afield of those spaces. The open areas act as a draw for such crossings, and the manpower needed to interdict that traffic is far higher without it — even if technology existed to detect every such intrusion over hundreds of miles.

Frankly, this clip makes the case for more barriers, as Trump is demanding, and rebuts the case that the traffic over the southern border is in any way manageable without them. They aren’t the entire answer, but it at least would make border patrol and humanitarian efforts a lot more efficient. (Front-page photo from DHS report via NBC News at the links above.)