Qdrop 2501 and Presidential Authorities

The US Constitution designates the President of the United States under Article 2 Section 2 "The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States."

Congress is required to make the laws by which the military operates and in Article I Section 8 specifies, "To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;".

So as Commander-In-Chief, the President can call forth the military to construct the Wall for national security and provide support as neccessary to ensure immigration laws (8 USC Ch 12 Immigration) are enforced and national security and defense (10 USC Ch 13 Insurrection and Title 50 USC War and National Defense) are enforced to protect the citizens.