The presidential campaigns are blowing smoke so thick that some voters are having a hard time peering through it.
But both are using a time-tested tactic in trying to define their opponents' weaknesses while distracting voters from their own, experts say.
"Politicians are very careful to not make definitive statements that can be disproven easily. They speak in generalities typically, so that what they say is not completely false, or has room for conjecture," said Ron Riggio, an organizational psychology professor at Claremont McKenna College.
"Voters are confronted with a firestorm of contentious ads, each followed by an immediate and aggressive denial, almost all of it devoid of evidence," said Joe Urbany, a University of Notre Dame marketing professor who studies the impact of negative campaign advertising. "It's impossible to distinguish fact from conjecture from fiction."