Seven years ago, during a previous immigration debate, Congress — including then-Sen. Barack Obama — voted overwhelmingly to build that much two-tier fencing along the 1,950-mile U.S.-Mexico border. But in 2007 Congress quietly backed off and gave the Bush administration the authority to cut the number of miles, and to scrap the two-tier fence.
Instead, the border now has 651 miles of barriers, and only 352 miles of that is an actual fence to keep pedestrians out. The other 299 miles are vehicle blockades that still allow wildlife, and people, to cross unhindered.
Homeland security officials say they are comfortable with the amount and mix of fencing, but many lawmakers say more is needed — and Mr. Thune’s amendment will give them a chance to have a say.
Still, it is expected to fail as the Gang of Eight senators who wrote the immigration bill defends the core of its deal, which is to offer quick legal status to illegal immigrants but withhold full citizenship rights until…