In isolation, each candidate’s strategy last night made sense. If Biden can’t stop Bloomberg from cutting into his support among African Americans, the former vice president will lose South Carolina and be out of the race. Buttigieg and Klobuchar occupy the same midwestern-centrist niche. A billionaire who has bought his way into the top tier of the Democratic presidential race is Warren’s perfect foil.

But the result, in the aggregate, was that the attacks on Sanders were glancing, predictable, and largely forgettable. Everyone attacked Bloomberg. The former New York mayor—who would have helped himself by counterpunching against Sanders, who leads him in the polls, instead shrank into the political equivalent of a fetal position.

To grasp how much Bloomberg’s participation in the debate helped Sanders, imagine what would have happened had the DNC not let Bloomberg in. In all likelihood, Buttigieg, Klobuchar, Biden—and perhaps even Warren—would have focused more of their wrath on Sanders. And it might have worked because Sanders this week made a mistake that left him vulnerable.

Last November, after Sanders suffered a heart attack, ABC News and The Washington Post asked Democratic-leaning voters which candidates were healthy enough to be president. Eighty percent answered Elizabeth Warren was. Seventy-four percent said Joe Biden was. For Bernie Sanders, the figure was 48 percent. Since then, Sanders has largely evaded this political liability. But it returned this week when he told a CNN Town Hall that he wouldn’t release his medical records, and a campaign spokesperson likened the issue to birtherism.

Sanders’s health is a legitimate issue for voters to consider. And he has no good answer for why he won’t release his medical records. Had his opponents pressed the subject as forcefully as they pressed Bloomberg on stop-and-frisk and mistreatment of women, they could have made that vulnerability the story of the night. They didn’t.

So the result of the Nevada debate is that Bloomberg, who was emerging as Sanders’s strongest rival, got knocked around. Which makes it harder to tell who is in second place. Which is great for the guy in first.

The Democratic establishment is both terrified of its front-runner and incapable of taking effective, unified action against him. Sounds a lot like the GOP in 2016.

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