In other instances, the job was done with a single well-timed put-down.
"I'm up in the Senate most Tuesdays when they're in session," Vice President Richard B. Cheney told then-Sen. John Edwards (D-N.C.) in 2004. "The first time I ever met you was when you walked on the stage tonight."
That turned out not to be true. But for Edwards, it still hurt.
So the lesson seems to be: Make sure your lie is really devastating, since the fact that it's a lie won't matter much.
Imagine if the lesson from that debate had been a different one. Something like, "Hmm, this Cheney guy can't be trusted."