Protesters rally across the country to oppose Trump’s declaration of a National Emergency, something they describe as a power grab at the Southern border. Ari Melber breaks down how new legal challenges to Trump’s National Emergency are emerging from the ACLU and other groups and that Trump’s immigration guru, Stephen Miller, appears to be struggling to find any precedent for Trump’s latest move to fund a border wall. Member of Congress, Jan Schakowsky, tells Ari Melber that Congress may have to consider