I don’t think anyone ever took Bernie seriously at first. I think it was a ploy to have him bringing in the left vote, allowing her to stay in the middle. But Bernie’s following wouldn’t let him back down, even though he never really went after Hillary.
In short, let’s speculate what would have happened had Bernie NOT entered the race.
In that case, do you think that Elizabeth Warren would have entered the race? Did she stay out because she thought Sanders had seniority, or maybe she thought one woman running had the chance for history, but two women running would be mocked as a cat fight? Or maybe she thought she'd be accused of not finishing one term (like Obama)?
Who else might have challenged Clinton in the primary if Sanders declined? Would Democrats really have let Clinton run unchallenged?
-PJ