Mealey's (June 28, 2017, 1:18 PM EDT) -- WASHINGTON, D.C. — Organizations that oppose President Donald J. Trump’s executive order that a government agency may issue a new regulation only if it rescinds at least two existing regulations on June 26 filed a brief in the U.S. District Court for the District of Columbia arguing that the order — which would affect rules governing exposure to toxic substances — “offends the separation of powers by usurping the constitutional lawmaking power assigned to Congress and violates the president’s unambiguous duty to ‘take Care that the Laws be faithfully executed,’” pursuant to the Constitution (Public Citizen, Inc. v. Donald Trump, No. 17-253, D. D.C.)....