Check out some of the general election polls in 2014; Hillary was up 10-20 on everybody and was one of the most popular politicians in the country. Time in the spotlight as the presumptive nominee reminds people of what they don't like about you and leaves them imagining some perfect alternative who would do no wrong. If it seriously looked like Bernie would be the nominee for just one minute, his numerous and glaring flaws would become everyone's focus. Nobody's popularity survives long term scrutiny and a cranky old socialist is far far FAR away from the type who could overcome that.
Amen, this is why pointing to hypothetical match-up polls is no way to make the case that Sanders would be better against Trump than Clinton.
