Biden’s biggest remaining personnel decision meets heat from the left

The Biden administration’s top economic aides like him. Lawmakers on both sides of the aisle respect him. And investors lapping up the rewards of loose money seem to love him. Even a potential rival for his job has endorsed him.

Now the biggest force standing between Federal Reserve Chair Jerome Powell and a second term leading the central bank may be an activist left prepared to create a spectacle in the coming months before the critical decision by President Joe Biden.

Some progressive groups are mobilizing against Powell’s reappointment, calling...