Lights! Camera! Cage match! The White House lawn’s Octagon is ready for Trump’s 80th birthday bash

It looks from afar more UFO than UFC. Maybe it’s the kind of contraption that has carried space aliens to the White House to force a meeting with America’s leader. But come closer and you’ll see the contours of the eight-sided cage, 30 feet (9 meters) in diameter and shaped, with careful precision, like the MMA league’s signature Octagon. That is, a STOP! sign flipped on its edge, with wire-mesh sides and padded corners fitted with different sponsors’ logos: Morgan & Morgan, Bud Light, Dodge Ram, Corona Extra and Polymarket, which identifies itself as the world’s largest prediction market. Overhead...