On Monday, President Donald Trump moved to fire Lisa Cook, a Biden-nominated member of the Federal Reserve’s Board of Governors. He moved to fire Cook for “cause,” and that cause is clear enough: According to William Pulte, director of the Federal Housing Finance Agency, Cook allegedly committed mortgage fraud by lying about her principal place of residence for purposes of securing more favorable interest rates—and then failed to report her rental income from the properties, to boot. Trump’s move is the first time a president has ever tried to fire a Fed governor for cause, and Trump’s usual detractors have...