Why Trump can’t build U.S.-Mexico border wall with only executive order

WASHINGTON— U.S. President Donald Trump’s proposed wall along the U.S.-Mexico border cannot be built with only the executive order he signed Wednesday and its construction will require congressional approval, border experts and former federal officials said.

Trump can start the wall by shifting around existing federal funds, but he will need Congress to appropriate the $20 billion, and perhaps significantly more, required to complete the massive structure, the experts and former officials said.

“How is he going to fund it? You need money,” Rand Beers, an acting Department of Homeland Security (DHS) secretary in the Obama administration, said Wednesday. “He’s got to have the money. And you can’t reprogram all that money without congressional authorization.”

Trump’s order mandates that DHS Secretary John Kelly “immediately plan, design and construct a physical wall along the southern border.”

It is vague about funding but appears to acknowledge that congressional approval will be needed to finish the structure. White House officials said the former developer will probably personally oversee aspects of its construction.

Border security experts and former DHS and congressional officials said the project is a massive and difficult undertaking. In addition to the cost, they said, it would face engineering and environmental problems; fights with ranchers and others who don’t want to give up their land; and the huge topographical problems of the border, which runs through remote desert in Arizona and rugged mountains in New Mexico, as well as, for two-thirds of its length, along rivers.