So the moderator asked about America’s original sin — slavery — and Biden somehow got to turning on record players, which wasn’t an effort to coax the hipster vote away from Sen. Bernie Sanders (I-Vt.) no matter how much the millennials love vinyl. It was an incoherent, rambling illumination of the key knock on Biden: He’s too old. Former housing and urban development secretary Julián Castro, during the debate, and Sen. Cory Booker, afterward, made this argument, first indirectly, then directly, but they didn’t need to. Biden indicted himself on the age question.

If President Trump abandons “Sleepy Joe” for “RecordPlayerJoeBiden” on Twitter, the tattoo on Biden that is probably already permanent gets inked in bright colors. Manhattan-Beltway media may scoff at the single-phrase branding, but every marketer knows it works and works and works.

“Record player” is like Gov. Chris Christie’s campaign-killing knockdown of Sen. Marco Rubio at a New Hampshire debate. “There it is. There it is,” declared Christie onstage. “The memorized 25-second speech. There it is, everybody.” Rubio and his supporters gamely tried for days to argue that what Christie said didn’t matter. It did. It was over for the Florida Republican. A campaign-slashing branding of “robotic” stuck. Just as “record player” will.