There was a climactic moment Thursday afternoon as Majority Leader Mitch McConnell announced on the Senate floor that President Donald Trump would sign a compromise deal on border-security funding, but would also declare a national emergency to try to build his wall. What happens next will be a test of the mettle of Republicans in the Senate—though if the past is any indication, it’s likely to be more of an anticlimax.
The announcement, confirmed by White House Press Secretary Sarah Sanders, capped a tense afternoon, as the mood on Capitol Hill shifted from an expectation that Trump would sign the deal to jitters that he might not. McConnell’s announcement ended one acute, Trump-created crisis—the threat of a second government shutdown, starting Friday—but the expected emergency declaration creates another. (Trump is slated to sign the bipartisan deal on Friday morning.)
Republicans have warned Trump against declaring a national emergency for weeks. Their concerns spring from both principle and pragmatism. Emergency declarations are a gray area of the law and raise concerns about executive power. It isn’t clear how an emergency declaration to build a border wall would work, nor whether courts would approve it in the inevitable legal challenge to come. Senator John Cornyn of Texas, a close ally of McConnell’s, has said he opposes the idea because it could empower a future Democratic president to proclaim an emergency of his or her own.