Pakistan, Jan. 19 -- Typically, when a president wants to make policy, he has to negotiate a deal with Congress. Because that hasn't worked out for President Donald Trump in securing his border wall, he's tried to find another way to lock down the $5 billion he wants to build it. "I have the absolute right to do national emergency if I want," he told reporters on Wednesday. By Thursday night, administration officials were reportedly looking at reallocating funds earmarked for national-disaster relief in Texas and Puerto Rico, which were hit by hurricanes last year.

In making this move, Trump would explicitly attempt to circumvent the political process. But he would also be exploiting a long-standing fact about the U.S. government: Execut...