Why do all off Obama's supporters want her to quit? They say she can't win, that Obama has it in the bag. So, why do they care? The primaries will go on whether or not Hillary is in the race, so the states to come won't save money. Do they want to save Hillary's supporters from wasting their money in campaign contributions? Unlikely. Are they trying to save Hillary the ignominy of defeat? (Is it less painful to resign than to lose?)
Or could it be that they are afraid Hillary will win most of the remaining primaries and head into the convention on a roll?