Thinking about stuff that hasn’t worked before and probably wouldn’t work now for what I assume are good reasons that I don’t know: if whichever of the 2 is ahead picks the other as as an early VP, maybe they pool enough support to edge out Biden at the convention. Assuming they can fade the Russian and GOP collusion and dirty tricks, the VP resigns early (bc they probably don’t really want that job) and Buttigieg or whoever is nominated for new VP. Warren and Bernie seem to be cooperating now so why not go for it if the opportunity is there. In this fantasy I prefer Warren for POTUS but the other should be happy to see the bulk of their agenda pursued.