This is about trust and legacy.
President Obama is scrambling to save his reputation for honesty, and the damage that has already been done to the law that, in the public mind, bears his name: Obamacare.
He admits that he has to work hard to win back credibility with the American people - "that's on me," he said, admitting that the practical implementation of this huge change had been "fumbled".
His problem, as so often with politicians, goes back to a rash promise. He said that under his signature legislation - the Affordable Care Act - people would be able to keep their current health insurance. "If you like it you can keep it", he said.
That isn't true - many plans don't meet the higher standards of cover demanded by the law - some only offer insurance for really severe conditions, some don't cover giving birth, or going to the doctor or prescriptions and so on.
Naturally these slimmed down plans are cheaper, and that is exactly why some people want to keep them.
The Republicans have accused him of lying - and as he clearly has said something that is not true, it hurts.
It is no coincidence that a new poll shows 52% of Americans now don't trust the president - his worse ratings ever. He says he gets it, understands how upset people are, and understands he has to win but some credibility.
So people will now be able to keep their old plan for another year.
Making Obamacare work
There are a number of problems with the President's fix.
It is debatable if his reputation will be changed by a tweak that makes his original words true - for another twelve months. The bigger problem is that he has to stop the momentum that leads people to see this as a flawed plan that doesn't work in practice.
The ideology and the policy matter. Of course they do. But not as much as whether it works, and whether people like what they get.
There are plenty of arguments you could have about whether, say, the British NHS works better than the French insurance-based scheme or vice versa. There are lots of problems with both. But try to swap them and both nations would erupt. They might moan about the details but on the whole they like what they have and don't want it changed whole-scale.
Obama has to make Obamacare at least as popular, or his reputation will be dimmed.
In the short term today's announcement is designed to head off a revolt by Democrats in Congress, an alternative to them voting for a Republican bill that the White House says would undermine the law.
But it is also about the President's image and his legacy, whether his most important change to American society is seen as an imposed burden or a lifeline to better health.