1. President Trump declared a national emergency on the border with Mexico on Friday in an effort to access billions of dollars that Congress refused to give him to build a wall there.

The president asserted that the “invasion of drugs and criminals” coming across the border constituted a threat to national security and justified unilateral action. But illegal crossings are already down and critics are accusing him of manufacturing a crisis. Above, migrants waiting along the border fence in Penitas, Tex., on Feb. 1.

Mr. Trump acknowledged that his declaration would be litigated in the courts and even predicted a rough road for his side. Senate Republicans are now faced with the hard choice of defending their institution, which Mr. Trump is attempting to circumvent, or bowing to the president’s whims.