But can Sanders sustain that high-mindedness if it suddenly seems as if victory, not just adulation, might be within his grasp? And can he sustain it if — as seems to be happening already — his rising poll numbers (or even an Iowa victory) inspire the Clinton campaign to turn sustained fire on him?

The reality is that an insurgent campaign that actually wants to beat Hillary Clinton would need to exploit vulnerabilities besides her insufficient zeal for a single-payer health care plan. It would need to go after her, instead, at the intersection of policy and character — by linking the Bernie-Hillary difference on financial reform to the sordidness of the Clinton Foundation’s global fund-raising, for instance, or by tying her recklessness with State Department emails to the fecklessness of the Libya intervention, and then linking that intervention to the issue that helped cost her the Democratic nomination in 2008, her Iraq-era hawkishness…

Would Democratic primary voters actually want to hear this message? I’ve long been skeptical, given how accustomed the left has become to dismissing Clinton scandals as small beer and papering over the larger Libya fiasco amid snickers at the right’s Benghazi obsessions.