Sean Davis:
“…A review of existing federal laws makes clear that President Donald Trump has clear statutory authority to build a border wall pursuant to a declaration of a national emergency. Arguments to the contrary either mischaracterize or completely ignore existing federal emergency declarations and appropriations laws that delegate to the president temporary and limited authority to reprogram already appropriated funding toward the creation of a border wall between the United States and Mexico.
To analyze the legal basis for Trump’s declaration of a national emergency and subsequent transfer of existing appropriations to respond to the declared emergency, we must begin and end with the actual text of underlying federal laws governing presidential declarations and appropriations of federal funding. The most important text regarding the latter is Section 9 of Article 1 of the U.S. Constitution: “No Money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law[.]”
This law is what grants Congress the so-called “power of the purse” and effectively makes Congress the most powerful branch of the federal government. Not one dime may be spent by the federal government in the absence of an act of Congress. As a result, no mere declaration of emergency by the president is sufficient to allow the expenditure of funding that Congress has not already appropriated.
Much news coverage of Trump’s national emergency declaration has suggested that he is unilaterally spending money that has not been appropriated to fund construction of a wall (or fence, or security barrier, or whatever you want to call it) on the U.S. southern border, but that is simply not the case. In fact, the formal declaration of a national emergency on the U.S.-Mexico border cites two specific federal statutes that provide him the legal basis to use emergency funds to secure the border: one authorizing the president to declare national emergencies (50 U.S.C 1601 et. seq.) and the other authorizing the president to reprogram existing federal appropriations in response to an emergency declaration (10 U.S.C. 2808).
Between 2001 and 2014, according to a January 2019 analysis by the Congressional Research Service, Presidents George W. Bush and Barack Obama used those two laws in tandem 18 separate times to reprogram existing appropriations to address national emergencies, so there’s nothing unusual or unprecedented in Trump using the same authorities to respond to national security threats…”