So what explains the Bass boom on the left? Look to her comment to The Atlantic: She “cannot envision” ever running for president, even if she was vice president.

The left is clearly worried Biden’s VP pick will be the Democratic Party’s leader in the very near future, and it won’t be a progressive populist like Warren or Baldwin. Biden has said he wants somebody philosophically “simpatico” whom he can trust to take on major responsibilities. And with Biden leading Donald Trump by healthy margins in nearly every poll, it’s very hard to argue Biden must shelve that desire and, out of political expediency, name a left-wing running mate to energize the party’s base…

If Biden is going to choose a fellow pragmatist, the left would greatly prefer the choice be someone who won’t seize the inside track for the next presidential primary contest, which could be as soon as 2024. Assuming Bass doesn’t change her mind about a promotion (or want to extend her presidency after the tragic event of Biden’s untimely demise), her selection would ensure a wide open primary contest in which a devout progressive, or even a democratic socialist like Rep. Alexandria Ocasio-Cortez, would have a better shot of winning than one including a sitting vice president.