This is what most of our southern border looks like: there is no government-built fence at all. There is often just whatever is left over from some forgotten cattle fence, built privately to keep U.S. cattle from wandering freely into Mexico. For hundreds of miles there is not even a broken cattle fence, there is nothing at all.
For comparison, below the broken cattle fence photo is a sample of an inexpensive but highly effective double border fence system, with a plowed strip to reveal footprints. This type of system is very cheap and can be built with great speed.
Here is what some of San Diego County has: a wall made of rusty Viet Nam-era runway mats. The corrugations are even horizontal, (to make climbing easier?) The illegals in this photo were spotted by unexpected civilian volunteers, and jumped back over the border.
Here is what the border looks like where the runway mat wall exists. Mexico begins on the other side of the ineffective rusty wall, which actually helps the smugglers, by hiding their movements until the occasional USBP vehicle has driven out of sight.
This is how "the game" is played. Smugglers hide on the other side of the wall with their dope and/or their illegals, out of sight of the USBP. They wait for the highly visible white BP vehicle to drive over the distant hills. Lookouts with cell phones and walkie-talkies report on the current locations of the BP units. They know with certainty that "the coast is clear" for an hour or two, and the smugglers and illegals hop the fence and run into the scrub only 50 yards away. From there, they are out of sight, and they walk 1-2 miles to holding houses. Then they wait for nightfall, and are picked up and driven in vans to LA or San Diego.
Lastly, below is the Duncan Hunter 15' fence, which is already being built along a few "showplace" miles of San Diego, mainly near the ports of entry, where panderng politicians can conveniently show it off to gullible reporters. The House has approved building 700 miles of it, which would be a great start. As you can see, the rusty runway wall is seen at the left side, Mexico begins on the other side. In areas with the 15 foot fence, dope smugglers and illegals will have to cross the open sand ("the government road" as it is called) before starting to try to get over the 15 foot fence. It's extremely tough, and resists cutting. Attacking the fence would have to be done right out in the open, in full view of cameras. This type of fence, on the U.S. side of the government road, will give the USBP a barrier to patrol, instead of forcing them to chase illegals around 100,000 square miles of wide-open frontier land, which is a fool's errand.
This is the fence the WSJ opposes, precisely because they know it would be effective, and would cut off their endless flood of dirt-cheap illegal alien labor.