One of Trump’s rocky moments toward the end of the debate was his answer on birtherism. It makes no sense for Trump to reach out to African-Americans in the hopes of getting a small increment of additional black voters — and showing suburban voters that he’s not a Neanderthal — at the same time he concocts a defense of his obsession with birtherism that is very likely going to be offensive to those same voters. The root of the contradiction is Trump’s unwillingness to admit error. If he didn’t have this aversion, he could button-up the birther controversy by saying, “Yes, I had these suspicions. I now realize I was wrong and I’m sorry if I offended anyone.” That takes about three seconds to say and he could revert to that reply whenever the topic — not an especially pressing issue in this election — comes up and be done with it. But this avenue is closed off to Trump. No one wants to be, or should be, in a defensive crouch all the time, but sometimes a mea culpa can actually get you off your back foot.