He's left of modern American Democrats (who as a party are center right typically).
People who have only experienced politics as the American team sport with Republicans on the right and Democrats on the left really don't have much understanding of what left, center, and right are. I'm frankly glad to see more candidates entering the field to broaden perspectives and challenge the notion of "what could win".
Frankly, Democrats could learn a lot from him. And Republicans probably could too, to be honest.