I don't think the populist left movement can be seen as a direct analogue to the tea party because they already have a framework for their political ideology and grassroots mobilization in Bernie Sanders' primary campaign, whereas the tea party had to build everything from scratch. A more obvious point is that there is no Democratic parallel to Mitt Romney, who was a pretty clear frontrunner even before the primaries began. If there's a similar figure around which the Democratic base can consolidate early in the process, I really don't see one right now.
Sorry, but what I bolded there is simple not true.
