...On Wednesday [Jan 25, 2017], Mr. Trump signed an [Executive]order to build it [the wall] and announced that work would begin immediately on a project that is estimated to cost more than $20 billion. He offered few details, including any that would address the fact that Congress, not the White House, writes the checks. The Antideficiency Act prohibits the government from spending money for any reason that Congress has not appropriated.(snip) So is Mr. Trump’s executive order meaningless? Not entirely. The Department of Homeland Security can start planning and discussing the project now and ask for the bulk of the...