This was the irony of Obama, and why he won so easily. The left assumed he was one of theirs because of his bio and they didn't make him 'prove himself' to them, yet Obama was a much more conservative Dem than Biden or Harris, or Bernie, or Warren, and that came through to the rest of electorate, whom he was able to make feel comfortable with him.
The DNC appears to be a disaster, but Party orgs today aren't that relevant at the Presidential level - In the TV/Video age presidential politics is personal. A strong Dem can win regardless of what the DNC is doing.