It really is as simple as that.
Even if Hillary were to surprise us all by performing well in forthcoming Obama-favoured contests in states like Oregon and South Dakota - even then, her victories would change the underlying arithmetic of the race so little that the impact would be minimal.
Her speech began with an odd line about going all the way to the White House and some commentators reached for their hard hats. But Bill didn't look as if he was going anywhere and nor is she.
Having said that, Clintons being Clintons, this could still run and run but only into the ground. One of her fundraisers told me in the middle of the night that a large sum of money to be clinched tomorrow will now be lost.
You stop running when the money runs out and the money will now run out. There is no argument to make to the super-delegates.
Could she run on just to secure the vice presidency, in a more genteel minor key, perhaps, a la Republican runner-up Mike Huckabee?
And talking of Mr Huckabee, I see that he is still doing rather well in the Repubican non-race.
Will that 12% of Huckabee voters go somewhere else in November?