At a moment when the architects of artificial intelligence are themselves stepping away from their creations in alarm, Senator Kennedy has moved to give the federal government the power to pull the plug. The legislation arrives not from the margins of public anxiety but from the center of the industry itself, where researchers who spent years inside the most powerful AI laboratories are now warning of imminent and immense harm. It is a rare convergence: the builders and the lawmakers arriving, by different paths, at the same unsettling conclusion — that the technology may be outpacing the huma