Barack Obama’s victory is good news for reversing one of the great environmental and humanitarian crimes of the Bush era: the U.S.-Mexico border wall.

The wall, about 280 miles long, is a disaster for the wildlife, landscape, people, and economy of the American Southwest. It prevents highly endangered species like jaguars (U.S. population unknown), ocelots (U.S. pop. ~ 80), and Sonoran pronghorn antelope (U.S. pop. ~ 100) from reaching the breeding populations south of the border that they need to survive, threatening the endurance of these great symbols of the Southwest. It also breaks up families that have straddled the border for centuries and threatens the economy of the border region, many parts of which are heavily dependent on birders, naturalists, and other tourists who come to admire the unique fauna.

Most politicians and border residents have always known that a 10-foot wall won’t do anything to stop an immigrant with an 11-foot ladder, but few had the guts to stand up to anti-immigration extremists in the Republican party. But watch Obama pledge to tear down (most of) the wall in his February 21 debate with Hillary Clinton — and pursue a different set of immigration policies to keep the border actually secure:

Embedded video from CNN Video

That’s exciting news — and it’s a move that will likely have popular support, especially in the border communities that know how damaging the wall is to the environment and to positive relations with Mexico. During my 2007 investigation of the wall, I interviewed mayors, law enforcement officials, and many local citizens about the wall, and most of them shared the view articulated by McAllen Mayor Richard Cortez:

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. But if you really want a security problem, have Mexicans hate the United States, and I’ll show you a security problem.

Not surprisingly, the border wall was one of the top issues in the election in the border region, where the wall is mostly unpopular. Although McCain also expressed opposition to the wall in wilderness areas, Obama was seen as the more anti-wall candidate, and he won 57 percent [.xls file] of the vote in the 24 counties along the southern border. Nationally, immigration has declined significantly as a topic of importance as people have focused more on the economy — according to a recent Pew survey, it’s the 11th most important issue for Americans.

The opposition to the wall will help Obama fulfill his promise, but it’s going to take his Homeland Security chief to actually implement the reversal of Bush’s disastrous border policy, which is why many in the border region are rallying around Representative Jane Harman (D-Calif.). As the former ranking member of the House Intelligence Committee and current chair of the Homeland Security Subcommittee on Intelligence & Terrorism Risk Assessment, Harman knows her way around the Homeland Security bureaucracy, and she had the foresight and backbone to oppose the wall when few of her colleagues did.

Regardless of who gets the post, however, Obama and his Homeland Security Chief will have to act quickly to remove the wall. The wildlife of the Southwest is already in a precarious situation, and without access to Mexico, they could go extinct rapidly. In one drought in 2001, the population of Sonoran pronghorn antelope declined from over 200 to 21 in the course of a summer; they’ve since recovered to about 100. Without quick action, almost anything could push them back to the brink.