Under pressure from the Fox News programs he watches on television, Donald Trump has declared that the absence of his demanded "border wall" now constitutes a supposed national emergency. This gives Trump broad theoretical powers to siphon money from other parts of government toward his own vanity project, to the tune of billions.
That's the Trump administration's theory. In practice, declaring a national emergency in the absence of any true emergency is considered legally dodgy at best; most experts who have weighed in believe that the courts would largely block moves to reappropriate federal money allocated by Congress to other projects as unconstitutional end runs around the legislative branch. Asked directly whether she and House Democrats would mount a legal challenge to such acts, House Speaker Nancy Pelosi confirmed that that was one of the responses she would be examining.
"I may. That's an option. I will review our options. But it's important to note that when the president declares this emergency, first of all, it's not an emergency, what's happening at the border. It's a humanitarian challenge to us ... the president has tried to sell a bill of goods to the American people."
Pelosi characterized the would-be emergency multiple times as an "end run around Congress", noting it is an "illusion [Trump] wants to convey." She also noted explicitly that, under this new Republican theory, a future Democratic administration could use the same premise to declare a national emergency over Democratic priorities that current Republicans have refused to take on.
"You want to talk about a national emergency? Let's talk about today, the one year anniversary of another manifestation of the epidemic of gun violence in America. That's a national emergency. [...] But a Democratic president can do that, a Democratic president can declare emergencies as well. [...] The president is setting here something that should be met with great unease and dismay by the Republicans, and of course we will respond accordingly."