The cover-up of former President Joe Biden’s age-related decline is as much a media scandal as a political one. An appropriately skeptical press would have asked consistently penetrating questions about the oldest president in history and continued to press the issue when it was clear the White House was hiding something (often, the president himself). Instead, they often supplied a megaphone to the defenses of Biden in what were meant to be straight news stories. If political advisers are always supposed to present the principal in the most favorable light they possibly can, though some new Biden details suggest this went well beyond any normal advance work, the media are not supposed to do anything of the sort. That is why the reappraisal of Biden’s physical and mental abilities while in office has so far...