Gavin Newsom is perfecting the art of inflating his presidential prospects by denying them

In the spring of 2019, when Joe Biden was just a battle-scarred former vice president, Barack Obama greeted his newly announced presidential campaign by praising his own selection of Biden as “one of the best decisions he ever made.” But he stopped conspicuously short of endorsing his old running mate. Biden quickly offered a credulity-straining explanation of the omission. Because he believed the eventual Democratic nominee should “win on their own merits,” he told reporters, “I asked President Obama not to endorse.” If you believe Biden did not want the nation’s most prominent and popular De...