The president has no constitutional authority over border control, which the Supreme Court has long found rests in the hands of Congress. Under Article I of the Constitution, only Congress can fund the construction of a wall, a fence or even a walking path along the border. And the president cannot slap a tax or tariff on Mexican imports without Congress.This, mind you, is coming from an unindicted war criminal who once argued that the President has the authority to order the crushing oof a child's testicles.
Nor can Mr. Trump pull the United States out of Nafta, because Congress made the deal with Mexico and Canada by statute. Presidents have no authority to cancel tariff and trade laws unilaterally.