Yglesias:

• gives a bit of behind-the-scenes about why unions didn't fully back him last time
• shows Sanders addressing his foreign policy weakness
• addresses the age thing
• looks at why Warren won't work as an alternative
• talks about how Sanders has "moderated" his views (which to me looks 90% like the Dems have come around to his way of thinking and 10% a misunderstanding about what happened with Heath Mello).