In the general election, Bernie would be more competitive

Former New York City mayor Michael Bloomberg and former Massachusetts governor Deval Patrick recently jumped into an already crowded race for the Democratic nomination. Politically, they hope to appeal to center-left voters rightly worried about Joe Biden’s flagging early-state poll numbers. Ideologically, they have cast their candidacies as efforts to save a fading breed of centrist Democrat. Neither Bloomberg nor Patrick is likely to win. Instead, for the first time in recent memory, two leftist candidates stand a good chance of seizing the party’s nomination: Senator Bernie Sanders of Vermont, and Senator Elizabeth Warren of Massachusetts.

To many observers, Sanders and …