It really doesn't matter whom the Democrats nominate, as long as they beat Trump and take the Senate

On this, I fear Krugman is correct.  A Democratic Senate will not go along with a lot of what a President Sanders or Warren want; a Democratic senate will make progress on healthcare, guns, and other issues even under a President Bloomberg or Klobuchar.   No Democrat can win without huge African-American turnout, so we can only hope that Mayor Pete goes away (quite apart from his vacuity).  A Bloomberg-Abrams ticket surely has as good a chance as a Sanders-Abrams ticket, and maybe better, because lots of Repugs might vote for Bloomberg.  But I do hope Democrats don't forget that ousting the Mafia Donald is important.  Global capitalism will continue to eat everyone alive, but even Bernie Sanders isn't going to change that:  he would just plug a few more holes in the dam than Bloomberg.

UPDATE:   This post certainly pissed off some Sanders fans on Twitter!   Warren and Sanders are the only presidential candidates I've ever given money to.   I wish I were as confident that Sanders can win as some others are:  the evidence is mixed.  I certainly hope he can (Warren is fading at this point, my guess is it comes down to Sanders and Bloomberg, who will pick up the Biden and Mayor Pete votes as Mayor Pete gets destroyed in the South).