The concrete wall rising along the Mexican border is supposed to help keep illegal immigrants out of America. But it's precisely because it will do nothing of the sort that its politician defenders are willing to throw billions of dollars and hordes of political capital into constructing it.
Those politicians know something they hope their constituents won't figure out: Walls don't work.
A 10-foot wall does nothing to stop someone with an 11-foot ladder. The Border Patrol has admitted that there are dozens of tunnels under the wall. People fly over in small airplanes. More than 40 percent of illegal immigrants to this country come here legally and then overstay their visas.
There are ways to reduce the flow of illegal immigrants: more border security guards, deployment of a high-tech "virtual fence" (though technical glitches are slowing this down), vehicle barriers and (above all) enforcing America's immigration laws, including penalties against employers who hire undocumented workers. Indeed, according to border mayors and law enforcement officers I interviewed, the wall will perversely weaken our border security.
"We're fortunate that right now Mexicans have positive feelings about America and have provided invaluable assistance to the United States in several criminal investigations," McAllen Mayor Richard Cortez told me while I was investigating the wall for Grist Magazine. "But if you really want a security problem, have Mexicans hate the United States, and I'll show you a security problem."
A working solution is exactly what the corporations who fund politicians' campaigns don't want. Cracking down on illegal immigration would interfere with the flow of cheap, nonvoting labor they use to keep wages low and bust unions.
The great tragedy of the wall, however, isn't just the colossal waste of taxpayer money that's being funneled to build it. Its true lasting impact will be the scar it leaves on the landscape of the Southwest and on the wildlife of our great nation.
Illegal immigrants will find a way to tunnel under, climb over or go around the wall or just violate their visa terms as long as people are willing to hire them. Those options aren't open to the endangered jaguars, wolves and jaguarundi that need to cross the border to survive.
Ocelots need so badly to go to and from Mexico that they've been tracked swimming across the Brownsville Ship Channel, 250 feet wide at its narrowest point. That option would be shut forever to them if the wall is built. Irresponsible Bush administration border activity already has reduced the remaining American herd of Sonoran pronghorn antelope to 20. There were more than 500 when President Bush took office.
This wildlife massacre will have devastating economic consequences as well. The Rio Grande Valley is one of the top bird-watching destinations in the world. It's a unique place in America that's filled with tropical birds that fly from Central and South America to nest, filling the trees and the air there with glorious song and flashes of lilac, saffron and crimson feathers.
Birders visiting the area pump $125 million into the Texas economy each year and support thousands of jobs. Few people want to come all the way to South Texas to stare at a concrete wall.
The twisted logic of the wall requires destroying America to save it. But we need a new logic - fast. Homeland Security Secretary Michael Chertoff just waived 37 laws - among them the Endangered Species Act, the Safe Drinking Water Act, the Native American Graves Protection Act and many others - to give himself the legal authority to build the wall.
Chertoff's constitutionally groundless action is being challenged in the Supreme Court, but a decision is unlikely to come before the Bush administration's politically connected contractors start pouring concrete. The administration is anxious to complete the wall before a new president takes office; all three candidates have expressed opposition to having a border wall on sensitive wild lands.
To achieve action faster, Congress must cut off funds for the wall immediately. That won't happen unless constituents demand that they stop having their intelligence insulted with a border wall that wastes our money, devastates our natural wonders and doesn't work.