As Enoch Powell once said, "All political careers end in failure".
And so it is with trade union bosses. David Hart's failure to persuade his members to keep faith with the workforce agreement, warts and all, is no doubt a cause for rueful regret.
But did he really fail? Or was it, as one delegate to next week's Professional Association of Teachers would argue (page 7), a case of "deferred success"? As he heads for retirement, Mr Hart must hope his beloved union can maintain the influence so ably built up by him over a quarter of a century of distinguished service. His success, currently deferred, was founded on positive engagement with government and enviable communication skills that he used to promote the role of heads as leaders in education. He will be a hard act to follow.