At some point the lying has to stop, right? But when? I'm no longer convinced that any external stimulus can reverse a liar. People don't lie because of a lack of penalties; getting in some sort of trouble is part of the action.
I suspect that any revision of a liar's behavior can only come from within. But I have no idea how a liar, whose natural state is one of defensiveness, can be made to acknowledge the consequences of their misdirections. That's the scary part of living in our current political climate.