Sierra Club and Defenders of Wildlife have filed an appeal with the U.S. Supreme Court challenging elements of the REAL ID act, which gives Secretary of Homeland Security the power to waive any environmental laws that would get in the way of the 700-mile-long double-layered concrete wall Congress authorized for the U.S.-Mexico border.

From the press release announcing the lawsuit:

By granting one government official the absolute power to pick and choose which laws apply to border wall construction, the REAL ID Act proves itself to be both inherently dangerous and profoundly un-American. The issue here is not security vs. wildlife, but whether wildlife, sensitive environmental values, and communities along the border will be given fair consideration in the decisions the government makes,” said Rodger Schlickeisen, president of Defenders of Wildlife. “We are hopeful that the Supreme Court will take up this case in order to protect the fundamental separation of powers principles enshrined in the United States Constitution.”

The lawsuit seems to have some legs; a government official familiar with it said it had some chance of success.

The suit is an encouraging and important development for the Sierra Club and Defenders of Wildlife, which have done significant local organizing to stop the border wall construction, but have been wary of engaging too aggressively on a national level because of the polarizing immigration debate.

But with more than 100 miles of wall already built and endangered species like ocelots, jaguars, and Sonoran pronghorn antelope threatened with extinction in the U.S. as a result, both groups have realized that this is not the time for caution.

The politics of the wall have also changed: McCain, Clinton, and Obama (who all voted to authorize the wall in the first place) have now questioned its effectiveness and fretted about the environmental consequences — a signal that if environmental groups can build a strong enough national movement against the border wall, there may be hope for the imperiled wildlife and landscape of the Southwest.