When I watched the now-famous (or infamous) first debate between Obama and Romney I was surprised by the unanimous opinion that Obama lost. I thought Romney benefited by being able to present himself directly to a large audience, without the filter of a largely-hostile media, but I didn't think Obama was inferior to him in terms of facts, policy ideas, etc.
Then in subsequent debates, Obama acted angry, spoke in a louder voice, interrupted Romney and generally was more assertive, and that apparently made him seem smarter, as the polls of TV viewers revealed that Obama had won.
I was struck by how Robert Anton Wilson managed to explain to me what had happened, in his discussion of the Anal-Territorial System in Chapter 18, "Multiple Selves and Information Systems," of Quantum Psychology:
This system makes a feedback loop between muscles, adrenalin, the thalamus of the brain, the anus and the larynx. Swelling the body and using the larynx to howl (muscle-flexing and noise) makes up the usual Domination signal among birds, reptiles, mammals and politicians. Study the speeches of Hitler and Ronald Reagan for further details, or just watch two ducks disputing territory in a pond.