Today, the Federal Reserve is at a critical juncture in its evolution. Unlike any prior period in U.S. history, the Fed now faces increasing demands to expand its policy objectives to tackle a wide range of social and political problems—including climate change, inequality, and foreign and small business aid. This Article develops a framework for recognizing and identifying the problems with “central bank activism.” It refers to central bank activism as situations in which immediate public policy problems push the Fed to aggrandize its power beyond the text and purpose of its legal mandates, which Congress has established. To illustrate, this Article provides in-depth exploration of both contemporary and historic episodes of central bank ac...