One remarkable feature of the debate over the situation on the U.S.-Mexico border is how little some commentators seem to know about what the Trump administration is doing. Pundits regularly get facts wrong. Talking heads engage in passionate arguments over dubious premises. Confusion reigns.

Much of the blame goes to the commentators themselves, who do not appear to have tried very hard to find out what is going on. But some blame also goes to the administration, starting with President Trump himself, which has often been unclear about its plans. So here, in the interest of clarity, is what officials say is happening:

First, the Department of Homeland Security says there is currently some sort of barrier on 654 miles of the 1,954-mile border. Some of it is high-quality fencing that greatly discourages illegal crossing. But some of it is so old and dilapidated that it is not really a barrier at all. Some is fencing designed to stop vehicles but allow pedestrians to walk right through.

For almost all of its proposed construction, the administration has settled on a steel bollard design, or what the president has called "steel slats." It is a hybrid of a fence and a wall, and either word could reasonably be used to describe it. But since Democrats object so strongly to the word "wall," Trump has taken to calling it a barrier.

Homeland Security says it has already finished erecting about 35 miles of the barrier and is on track to increase that to 40 in the next few months. About two miles have been put in place at the El Centro Sector in California. (DHS divides the border into nine sectors, and that is how it cites the locations of new barriers.) Another 20 miles has been finished in the El Paso Sector in New Mexico. Fourteen more miles in the San Diego Sector in California are set for completion in May, with another four miles in El Paso slated for completion later this year.

Then, there are another 75 miles that DHS says are under contract or for which the contract and design process is underway. Those areas cover parts of San Diego, El Centro, the Yuma Sector in Arizona, and the Rio Grande Valley Sector in Texas.

Put it all together, and that is about 115 miles. It is all being done, according to DHS, with money that was available in fiscal year 2017 and 2018 appropriations.

All of that work replaces and upgrades existing fencing. It's the kind of work that in an earlier era might have been entirely uncontroversial.

The current fight between Trump and Democrats in Congress is over money for next year — $5 billion to build more barriers. If the administration were to actually get the $5 billion, officials say, it would allow DHS to build up to 215 additional miles of barrier, with about 65 miles being replacement barrier and 150 miles being new construction in areas that currently have no barriers at all.

The department has already announced where the barriers would go. There would be five miles in the San Diego Sector, 14 miles in the El Centro Sector, 27 miles in the Yuma Sector, nine miles in the El Paso Sector, 55 miles in the Laredo Sector in Texas, and 104 miles in the Rio Grande Valley Sector in Texas.

In all, counting work that is done, being done, and planned, the administration would build 330 miles of new barrier, 150 in areas with no barrier today.

All of it is a project that, in a less crazy time, might be the subject of bipartisan approval. Indeed, as the White House is fond of pointing out, bipartisan majorities in Congress voted in favor of an extensive border barrier back in 2006.

Politics aside, the bottom line is that even the relatively short lengths of barrier the Trump administration is building will do good. Just look at some of the fencing made from rusted steel helicopter landing mats from the Vietnam era. The administration is replacing it with imposing barriers that will discourage illegal crossings. That's a net plus.

And there is no doubt such barriers work. In San Diego, for example, a barrier has made a tremendous difference. "In the 1980s, migrants overran the border and the Border Patrol," the San Diego Union-Tribune reported in 2017. "Thousands gathered nightly on a small slice of the border ... there, men, women, and children waited for nightfall before making their passage." In 1986, agents apprehended an astonishing 629,656 illegal immigrants in the San Diego area.

When U.S. officials constructed one barrier, and then another, that number fell dramatically; by 2015, apprehensions fell below 30,000.

Now, the flow of migrants presents a new and different problem. While smaller than several years ago, it is largely made up of families and unaccompanied children who have no valid claim to asylum but who cannot, by U.S. law, be returned to their home countries. As long as those migrants can freely cross the border, they can stay in the United States — a situation that will attract more and more illegal immigration.

The president's proposal, which in addition to a barrier contains provisions for more immigration judges, more Border Patrol agents, more detention beds, more medical resources, and more technology, would improve the situation. If the political debate were not being fought at such an extreme pitch, that might be obvious to all.

