English Conservatives and Scottish Nationalists do not wake at 3 a.m., drenched in sweat, worrying about how they can defeat Jeremy Corbyn. Like a drunk who punches his own face, Corbyn beats himself, leaving Labour’s rivals free to do what they will. For English leftists, however, trying to salvage what they can from the wreckage of their party, the apparently simple question of how to take on the far left appears impossible to answer.