David Leonhardt: How the left can stop losing

How did the political left squander the opportunity that was the 2020 primary campaign?The Trump presidency has created tremendous energy among progressives. More than half of Democratic voters now identify as liberal. Most favor “Medicare for All.” A growing number are unhappy with American capitalism.This year’s campaign offered the prospect of transformational change, with a Democratic nominee who was more liberal than any in more than a half-century. Instead, the nominee no