It’s possible that, over time, all the insistent peddling of far-left policies will force almost the entire party into Sanders territory, especially considering impending generational shifts. It’s also possible that Joe Biden’s more establishment politics will catch traction and change the race. (It’s always hard to say whether this kind of movement is top-down or bottom-up.)
But had Clinton faced a more competitive primary in 2016, the mainstreaming of Sanders’s fringe politics may never have occurred, and Democrats in 2020 may have been facing a very different race right now. Maybe, just maybe, it would have been the kind of contest in which serious candidates felt comfortable blasting the notion of enfranchisement for the Boston Marathon bomber, rather than asking for “that conversation” to keep a certain bloc interested.