I would guess that you and I are about the same age.
I saw the same thing you see, and I saw it as early as the 3rd Debate. Remember the end when 0bama hugged Moochelle? It had the “it was fun while it lasted” look. Romney looked like a winner, Obama a loser, and both looked like they knew it.
My take was that through their expressions, we saw the internal polls they had just seen earlier that day.
I was 10 years old when Richard Nixon destroyed George McGovern in 1972. But already I was fascinated by politics. I watched the DNC and RNC conventions in their entirety - which quite amazed my parents.
I will admit to being for Carter in 1976. Hell, I was only 14 and still hadn't formed my ideology yet. But I was mesmerized by Reagan's RNC speech of 1980 and my conservative roots took hold. I went into Marine Corp boot camp in February 1981 and here I am today!