Bernie Sanders campaign is doing well.
He won the first three nominating contests.
However, he has a major problem: his admiration of Fidel Castro.
On 60-Minutes, Sanders praised Castro's Cuban literacy efforts.
CNN said that praise could become a long-term political headache for the Vermont senator's campaign.
During Tuesday's debate, Sanders pointed out that Barack Obama had made comments similar to his about Cuba.
"When dictatorships ...