Given Sanders’ lackluster poll numbers then, moderate Democrats and Republicans often built him up to use as a cudgel against Warren, especially when she was struggling to explain how she’d pay for “Medicare for All.”

“At least Bernie’s being honest here,” Sen. Amy Klobuchar of Minnesota said at the Democratic primary debate in October, while joining others on stage in criticizing Warren.

Billionaires like former Goldman Sachs Chief Executive Lloyd Blankfein and investor Leon Cooperman also trained their fire primarily on Warren, not Sanders, presumably assuming, like so many others, that Sanders’ time had passed and that he would soon hand off the baton of the progressive movement he started to Warren.

“None of his opponents have attacked him,” said Ian Sams, a Democratic operative who has now gone two rounds against Sanders — as a campaign aide to Clinton in the last election, and to Sen. Kamala Harris, D-Calif., in this one. “There had been a supposition all last year from media and the political class that there’s no way Bernie way could win, which was a pretty faulty assumption.”