Carney was right not to claim victory. The rollout of Obamacare this fall, particularly the president’s broken promise that people who like their health plans would be able to keep them, have damaged Obama’s credibility, probably permanently. Many people — including young voters who disproportionately supported Obama — have lost their catastrophic-coverage plans and now must pay significantly more to get new, bigger plans. And it’s still not certain that the health-care exchanges at the heart of the law will be viable.

But fixing the Web site after its embarrassing launch means that opponents of the Affordable Care Act have lost what may have been their last chance to do away with the law. And supporters can rule out the worst-case scenario: Obamacare isn’t going away. Even some conservatives have begun to tiptoe away from an opposition to the law that looked much like sabotage.

Last week, Rep. Jack Kingston (R-Ga.), a Senate candidate, told a local radio station, Z Politics, that “a lot of conservatives say, ‘Nah, let’s just step back and let this thing fall to pieces on its own.’ But I don’t think that’s always the responsible thing to do. . . . I think we need to be looking for things that improve health care overall for all of us. And if there is something in Obamacare, we need to know about it.”

In the White House briefing room, too, there was a change in tone.