Perhaps he was earnest to a fault. There wasn't much levity in this speech, but that's probably his way of making clear that he's not taking his new job lightly. He's not going to be the Frat Boy in Chief. Yes, it's a divided nation. But look at that stage.
Political foes are shoulder to shoulder.
There's the elder Bush and his wife Barbara, there's Jimmy and Rosalyn Carter. The Supreme Court justices. Senators from both parties. Coretta Scott King. The Clintons and the Gores.