That's it!
The liars who have been lying about Bush now are forced to say that Bush is lying about lying. That makes them liars about the lies that they claim Bush is lying about the lies they claim he is lying. Can their lies get more convoluted? The trouble with liars is that they lose track of their lies.
(If you can follow this perhaps you can clarify my confusion.)
Greeley is telling lies to back up his lies by claiming Bush is lying about lying. Simple.