What’s the difference between a calm and cool Barack Obama, and a rattled and worried Barack Obama? Four words, it turns out.

“You didn’t build that” is swelling to such heights that it has the president somewhere unprecedented: on defense. Mr. Obama has felt compelled—for the first time in this campaign—to cut an ad in which he directly responds to the criticisms of his now-infamous speech, complaining his opponents took his words “out of context.”

That ad follows two separate ones from his campaign attempting damage control. His campaign appearances are now about backpedaling and proclaiming his love for small business. And the Democratic National Committee produced its own panicked memo, which vowed to “turn the page” on Mr. Romney’s “out of context . . . BS”—thereby acknowledging that Chicago has lost control of the message.

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