President Trump on Friday declared a national emergency to redirect about $6.7 billion from programs in the Departments of Treasury and Defense to border wall construction. Less than 24 hours later, the declaration faces its first legal challenge: a lawsuit from Public Citizen, a progressive advocacy group, on behalf of Texan landowners whose property would be used for the wall. The suit argues Trump "exceeded his constitutional authority and authority under the National Emergencies Act" and asks that he be banned from "using the declaration and funds appropriated for other purposes to build a border wall."

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