Elizabeth Warren

I haven't seen anyone from the left run such a fierce and determined campaign ever, in my long life. Few people are willing to go up against power the he is, and of the few they are, most of them run token campaigns to get the message out, but don't really compete (that's what I expected from Bernie when he announced, a token leftist candidacy). Bernie was more than up to the task, absolutely amazing. Warren, on the other hand, seems to prefer much smaller fights that she can claim as victories, and was apparently unwilling to go up against the powerful Clinton machine.

I think there's a real chance she will run for VP with Hillary, though it's probably more likely Hillary will go with someone who appeals to her corporate donors more, and whose demographics will help her more in the general election (such as Castro).