Hillary didn't need the Superdelegates because she had enough votes from rank and file Democrats to seal the nomination. It was Bernie, who after the New York primary had no chance at winning the nomination, who sought the superdelegates to overturn the votes of the democratic base. Bernie had a ton of support from white, over 60 year-old, boomers and white under 30 year-old millennials but almost no support from the traditional Democratic bases in the African-American and Latino communities.

I think Single-Payer would be great. If you remember back to 2009 you'll remember that even the watered down version of the public option was impossible to pass. Us liberals in Seattle and San Francisco might think it's a no-brainer but our fellow 99%ers in Michigan, and Iowa, and Montana, and Alabama, think it's Communism. Americans might say they want single-payer, but only for themselves. Once Americans realize that single-payer means those "others" get it too, support plummets.