It was the movement that brought the magic to the Corbyn campaign. Although a process was already underway within the Labour membership, what gave the Corbyn phenomenon its distinctive character was the participation of people from outside the party. It was the sense that Jeremy Corbyn was at the head of a broad movement that made his leadership bid so extraordinary. The excitement; the dynamism; the heady, disorienting feeling of the impossible becoming possible—these were the trappings of movement politics.

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