Seems a lot of people have only seen his tattoo or heard about his reddit comments. I encourage you to watch some of his long form interviews or campaign events. The guy is demanding real change from the neoliberal norm and so threatens their sovereignty over the party, I'd be surprised if they ever endorse him.
Whether or not you're from Maine, if all you've seen is his controversies then you're in a specific news echo chamber that does not want to share his policies.