Shorter version of Emmett Rensin’s post at Vox.com: the Democratic Party has become elitist. The rest was inevitable. This stuff was all explained a century ago.
When the vanguard of the proletariat is distinct from the proletariat, it will inevitably become increasingly separated from the objectives of the proletariat. Darned proletariat just doesn’t know what’s good for them. Maybe that’s because it always involves being bossed around by the vanguard who get pretty busy flying from international convocation to international convocation in their private jets.