President Obama had the young vote, but he also had the black vote. Buttigeig will get some of the black vote in the general election, but not nearly to the degree that President Obama did. And it’s not just because President Obama was the he first black candidate in the general election. Much of the black community still doesn’t approve of homosexuality. It’s not that they’d instead vote for President Trump, but Buttigeig wouldn’t get nearly the turnout that President Obama did.
Buttigeig can rely on the youth vote and the urban white liberal vote. Rural democrats and the black community won’t show up to the polls for him.