Bernie’s campaign changed progressive politics, but not by its rhetoric. He’s literally been saying those things for 40 years, and none of those principles are new to those of us on the left. The campaign succeeded by proving multiple claims to the political class: There is a constituency for progressive policies, you can run a successful campaign on small donations, etc., etc. Restated: Bernie succeeded by proving the practical case to political elites that there are paths to victory that run through the left. Hence, he’s not blowing smoke when he says that this is the most progressive Democratic platform in history. He moved the Overton Window to the left. But that’s only a start.