Listen to that talking point: either he's not telling the truth or he doesn't know any better.
That's NOT going to sell. Saying the President is a liar or a dufus, especially during wartime, is going to turn people off.
Well, maybe not; the Dems have been saying that for 3 years and their candidate is still within single digits of the Pres. Apparently either someone thinks the Pres is a lying doofus, or the pollsters keep calling lying doofus'
IMHO