Many left-wingers despair of ever being able to influence events. With an unelectable leader, a divided party, and the Parliamentary Party in conflict with the constituency members, they fear annihilation at the next election.
I am happy to provide them with a scenario that offers hope. A Labour MP resigns his safe seat, possibly with the covert promise of a future peerage. Ed Balls stands as candidate and is chosen, riding the wave of his popularity gained on Strictly Come Dancing. He is returned with a massive majority in the by-election and promptly challenges for the leadership. He runs on a left-wing, but electable platform.
He wins the votes of ordinary Labour supporters, and some on the left who want a leader who can lead and can win. He wins, and as leader he unites the party and runs an effective opposition against the Tories. Come the next election the choice is between an electable Labour Party with a coherent programme and a charismatic leader and a Tory Party seen as competent and a safe pair of hands, with the kudos of a successful withdrawal from the EU.
It could be a close-run thing.