Incumbent has been granted four more years to make good on early hopes.
America has chosen and the world will be the better or worse for it. Anyone who doubts that a presidential election makes much difference to the course of events has already forgotten the first election of the 21st century. If a few hundred votes in Florida had gone the other way in 2000, there would have been no invasion of Iraq, the US response to 9/11 would have been different, and the world's response to climate change might have been more co-ordinated and well advanced by now.
It is harder to predict the consequences of the choice Americans made yesterday. President Obama had to run on his management of the economy, reminding the country of the mess he inherited and the steps he had taken to preserve the car industry and protect jobs generally. His re-election suggests a continuation of the slow recovery, but might he do more?
His first economic challenge is the "fiscal cliff" looming next month when tax cuts expire and spending reductions must be made. Together those measures would take money out of an economy still struggling to recover from the recession four years ago.
With the authority of his re-election, Mr Obama's hand should be strengthened in negotiations with the outgoing Congress. It will probably agree to extend the tax cuts and maintain present spending levels. But the President ought to be thinking further ahead. The election campaign was tougher than he thought it was going to be. Mitt Romney struck a chord with criticism of his economic leadership.