It’s the oldest debate within the Democratic Party: what to do about a progressive insurgent candidate? Whether it’s Ted Kennedy’s challenge against Jimmy Carter in 1980, Howard Dean against John Kerry in 2004 or Bernie Sanders against Hillary Clinton, moderates and centrists always say the same thing: in order to win, you need those swing voters. That means you have to pick the moderate choice. The problem with that argument is that it never really works out in the general election. Kennedy and Dean’s voters stayed home in November. 3 to 4,000,000 Bernie Sanders primary voters never showed up for Hillary Clinton. Now the same argument is being floated again, this time in favor of Joe Biden.