From a distance, the Sanders-Warren flare-up may have looked the same. But the contrast between Booker-Biden and Sanders-Warren is that Booker responded to something that Biden directly did (said), while in the second case, Warren didn’t do anything. Some other folks started talking her up. But Sanders’ people never miss a chance to reinforce the “it’s us vs. the world” narrative. That’s the driving motivation of the Sanders campaign. Their beef in this case isn’t with Warren. It’s with Third Way and the “corporate wing of the Democratic Party.” It was opportune, from Sanders’ perspective, that this happened during a week when everyone is chattering about how Warren is overtaking Sanders in some polls, moving into second place. And here, lo and behold, was a chance to tie Warren to the corporatists!

If one of these two quarrels is going to metastasize into something ugly, it’s pretty easy to see which one. Despite Booker’s tough words today, if Biden wins the contest, Booker will get behind him and campaign vigorously for the Democratic nominee. It would take a lot more than what Biden said for Booker to want to be seen by anyone as having not done his part to stop Trump. Likewise, if somehow Booker catches fire and is the nominee, Biden will back him in a heartbeat.

Sanders-Warren, though, has the potential to get bitter. If Biden pulls two or three more of these verbal gaffes, Democratic insiders are going to start worrying that he just can’t go the distance, and they’ll probably settle on Warren, at least as things stand now, because she has earned it (though it’s way too early to count out Kamala Harris and two or maybe three others).