Somebody somewhere will jest that this is all Bush’s fault.
It is a common belief on the right that Obama has blamed nearly everything bad that has happened on his watch on the previous administration. Now Obama will take credit for a rare success – the groundwork for which was laid down by his predecessor. Chances are, he won’t blame Bush for this one, so it is up to Obama’s critics to point this out.
So now you will understand the joke when you hear it.