We are so submerged in the details of this debate—whether the bill will include a “public option,” limit coverage for abortion, or tax Botox—that it’s easy to lose sight of the magnitude of the impending change. For the federal government to take responsibility for health coverage will be a transformation of the American social contract and the single biggest change in government’s role since the New Deal. If Obama governs for four or eight years and accomplishes nothing else, he may be judged the most consequential domestic president since LBJ. He will also undermine the view that Ronald Reagan permanently reversed a 50-year tide of American liberalism.

Obama’s claim to a fertile first year doesn’t rest on health care alone. There’s mounting evidence that the $787 billion economic stimulus he signed in February—combined with the bank bailout package—prevented an economic depression. Should the stimulus have been larger? Should it have been more weighted to short-term spending, as opposed to long-term tax cuts? Would a second round be a good idea? Pundits and policymakers will argue these questions for years to come. But few mainstream economists seriously dispute that Obama’s decisive action prevented a much deeper downturn and restored economic growth in the third quarter. The New York Times recently quoted Mark Zandi, who was one of candidate John McCain’s economic advisers, on this point: “The stimulus is doing what it was supposed to do—it is contributing to ending the recession,” he said. “In my view, without the stimulus, G.D.P would still be negative and unemployment would be firmly over 11 percent.”