The unspoken truth about the furor Buttigieg arouses is that his success threatens a core belief of young progressives: that their ideology owns the future, and that the rise of millennials into Democratic politics is going to bring an inevitable demographic triumph for the party’s far left wing.

The left believes the youth are on its side—and as shown by Bernie Sanders’ popularity among the under-30 set, as shown in a recent Quinnipiac poll, they’re apparently right. In a primary debate with the incumbent former Rep. Joe Crowley, Alexandria Ocasio-Cortez said, “I represent not just my campaign, but a movement.” Mobilized young Democratic Socialists of America members have raved to the New York Times about how the DSA is “what the Democratic Party should be.” Waleed Shahid, spokesman for the Ocasio-Cortez-aligned Justice Democrats, has dramatized the generational struggle by interpolating a famous Gramsci quote with his pinned tweet: “The old America is dying. A new America is struggling to be born. Now is a time of monsters.”

So it’s especially galling that the first millennial to take a serious run at the presidency is nothing like the left’s imagined savior. Buttigieg is a veteran, an outspoken Christian, a former McKinsey consultant, and, frankly, closer to Mitt Romney than Sanders or generational peer AOC in his aw shucks personal affect. In the eyes of radicalized young leftists, Buttigieg isn’t just an ideological foe, he’s worse than that: He’s a square.