Trump declares national emergency to build border wall, setting up massive legal fight.

The president signed a spending and border security plan into law to keep the government running through Sept. 30, with only hours to spare before parts of the government shut down Saturday. Before he did so, Trump also declared a national emergency to repurpose funds from other parts of the government to build his proposed border wall without congressional approval.

“I’m going to be signing a national emergency, and it’s been signed many times before, by many presidents. It’s rarely been a problem … nobody cared,” the president said during unscripted remarks Friday morning in the White House Rose Garden.

The president faces significant opposition to his action. The emergency declaration, which was criticized by Democrats and Republicans alike when Trump first threatened it, is likely to bring swift legal and legislative challenges. Already, it has sparked a fierce debate over executive authority, as critics argue Trump has manufactured a crisis to fulfill a campaign promise that was thwarted by Congres

Trump had pushed for lawmakers to approve $5.7 billion to build his proposed border wall. Instead, the divided Congress passed only $1.375 billion to construct new bollard fencing on 55 miles of the U.S.-Mexico border. By declaring a national emergency, and taking other executive action, the White House hopes to create a pool of $8 billion to use for barriers.

The president’s comments in recent weeks as he threatened an emergency declaration could hurt his legal case. He repeatedly framed it as a choice, rather than a necessity, raising questions about how urgent it really is. On Friday, he claimed: “I could do the wall over a longer period of time. I didn’t need to do this [national emergency]. But I would rather do it much faster.”

Dealt another political blow by Congress over the spending bill, the president has repeatedly argued he has the authority to reallocate money without the approval of the legislative branch. The emergency declaration, the administration claims, would permit the president to divert funds from other agencies, primarily the Department of Defense, to be used for the border project.