All the evidence indicates that left-winger Jeremy Corbyn is on course to win the British Labour Party’s leadership contest. The conventional wisdom on the British center-left — both within the party and among Labour-leaning media pundits — is that a victory for Corbyn would represent an utter disaster for the party.

The general thrust of their argument is that Corbyn supporters are unserious, unwilling to think responsibly about the necessary compromises of power, and are engaging in a form of narcissistic, self-indulgent “purity leftism” that, if Corbyn is successful in his leadership bid, is likely to condemn Labour to years of opposition in a tragic rerun of the party’s post-1983 “wilderness years.”

They’re wrong. For one thing, for all the warnings and finger-wagging in relation to the irresponsible, utopian dreaming purportedly constitutive of “Corbynism,” what Corbyn actually proposes in terms of policy is perfectly sensible and, in many ways, far too modest. His platform amounts, effectively, to a return to something like the form of Keynesian social democracy that was absolutely mainstream a few decades ago. That fact that these policies could be labeled “far left” shows how much public opinion has shifted among the British liberal-left since that time.