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There have been two polls of Iowa Democrats released in the past week. Bernie Sanders led one of them. Joe Biden led the other — but that poll’s sample appeared to be light on several groups of voters (like millennials) who often support Sanders, as Nate Cohn of The Times pointed out.

All of which points to the same conclusion: Sanders has a real shot of winning the Democratic nomination. Only a couple of months after he suffered a mild heart attack, that counts as a surprise. On the new episode of “The Argument,” Ross Douthat, Michelle Goldberg and I talk about the reasons for Sanders’s strong position, as well as about his strengths and weaknesses.

As you may know by now, I am not Sanders’s biggest fan. I think he exaggerates the degree of popular support for his agenda and, by extension, understates the difficulty of accomplishing it. I think a few of his ideas (like “Medicare for all”) are wrongheaded. I’m also uncomfortable with how little he has done to push back against the aggression and nastiness of some of his supporters.