Yes, The President Can Declare A 'National Emergency' To Build A Wall
Snippet of Article: "...The president is correct Some scholars of presidential emergency powers say there is next to nothing, at least procedurally, that Capitol Hill could do to stop Trump from exercising what lawmakers of all stripes agree is his right to declare a national emergency. "Congress chose not to put any substantial — or really any — barriers on the president's ability to declare a national emergency," says Elizabeth Goitein, co-director of the Brennan Center for Justice's Liberty and National Security Program..."
Source: National Public Radio