He would probably never do that, but I wouldn't begrudge Sanders if in case of a contested convention and having amassed the most delegates he would go 'Your call, but if you throw this to Bloomberg you should plan on a scenario of him running against Trump and myself as Independent' of course Bloomberg could do that too and in fact might be counting on it. And then it will be a game of chicken with a 2nd Trump presidency as the cliff, or maybe they'll just give it to Klobuchar