Simply 'lying' just doesn't cover it. "Grubering" adds the necessary ingredient of arrogant, elitist, chutzpah that so dominates progressive thinking.
To me “Gruber” means: “to disdainfully, but truthfully, brag about one’s prior lying and deception”.
“Obama”: to say the opposite of the truth continually and obviously while laughing in the face of the public.