It’s not a “mistake” in the sense that the Democraps are a ruling class party that wants to exclude or marginalize anyone with even a hint of interest in alternative positions. Even recycled McGovernite liberals like Tusli and AOC. Notice that Tulsi, the most anti-imperialist of any of the Democrats, is also the one party goes out of their way to marginalize, much more so than Sanders, AOC, Yang, or anyone.