Are Democrats sabotaging their own socialists?

It's quite a claim, but Bernie Sanders has suggested that some Democrats would rather lose the Senate than support Abdul El-Sayed in Michigan and Angie Nixon in Florida.
These firebrand progressive candidates, Sanders claims, are too much of a threat to oligarchy and the US relationship with Israel for a minority of establishment Democrats to get behind. Is he right? And if so, what does it say about the depth of division in the party? Or is this really about who gets the presidential nomination in 2028?
Later, the Pulitzer prize winning biographer Kai Bird on how Donald Trump learnt the dark arts from Roy Cohn - and how Cohn has defined America's politics today.