John Edwards endorsed Barack Obama a few hours ago after dropping hints to the effect for the past week, and the predictable firestorm of debates over “the impact” and “what it means” has been launched. The fact is, the real impact of Edwards’ endorsement extends far beyond the 18 delegates he brings to the table, or whatever arguable measure of political clout he’ll provide. It was a strategic maneuver, and a goddamned genius one at that, at a moment that Hillary desperately wanted to call her own.