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“I know we’ve had some big polling misses in primaries recently, and that has everyone on edge,” G. Elliott Morris, a journalist and pollster who writes a Substack called Strength in Numbers , told me. Polls showed wide leads for progressive candidates in some key Democratic primaries over the summer: Abdul El-Sayed was predicted to win Michigan’s Democratic Senate primary by double digits but only eked out a victory. Francesca Hong’s big lead in Wisconsin’s gubernatorial primary turned into a loss for the Democratic Socialists.…