The rise of Sanders has triggered an ideological argument – is Sanders promoting bona fide socialism or, as Fredrik deBoer suggested in POLITICO Magazine last year, is he nothing but a “Socialist In Name Only?” — but the real divisions are tactical. In a presidential election year, even socialists have to think about electoral strategy. And Bernie’s rapid ascent means that the political decisions of the far-far left have been complicated by an unfamiliar surge of attention.

Some welcome it. Philip Locker, Seattle-based spokesman for the national Socialist Alternative organization, is thrilled by Sanders phenomenon, enthusing that “the political system is starting to be shaken” as Sanders “is popularizing socialism to an audience of tens of millions.”

To others, that’s dangerous naiveté. Howie Hawkins, a Green Party co-founder and member of the socialist group Solidarity, wrote an essay in May for the ISO’s Socialist Worker website attacking Sanders for “violating the first principle of socialist politics: class independence,” consorting with the “billionaire class” by pledging to “support their candidate” if he loses the Democratic primary…

Do you root for Bernie as an almost unique chance to get millions of people to think seriously about socialist ideals, or against him for planting a false flag of revolution? And if you expect him to lose in the end—which, to be fair, most socialists do—should you ride the train as far as it goes, or get off it now and throw your energy into the real revolution? Those are the questions bitterly dividing the movement, as Sanders himself storms energetically from one rally to the next.