The plotting is ridiculous, just as it was in “Olympus Has Fallen,” but Emmerich does a far better job with the over-the-top material. He recognizes and embraces the silliness of the story, turning “White House Down” into a bracing action film that is often funny and always entertaining. Tatum, of course, has a great deal to do with this. His natural charisma and impressive physique allow him to be witty and heroic simultaneously, and he is particularly good when playing across from Foxx.