Mr. Buttigieg has stirred suspicion among some Democrats for his hazy commitments on policy. In the liberal magazine Current Affairs, the editor Nathan J. Robinson ridiculed Mr. Buttigieg as a clever political marketer without ideas or a record undergirding his ambition.“He’s from the Rust Belt so he’s authentic, but he went to Harvard so he’s not a rube, but he’s from a small city so he’s relatable, but he’s gay so he’s got coastal appeal, but he’s a veteran so his sexuality won’t alienate rural people,” Mr. Robinson wrote. “This is literally the level of political thinking that is involved in the hype around Buttigieg.”There are policy elements in Mr. Buttigieg’s pitch, many of them tethered to the theme of generational change. He has called for creating a government-backed health insurance option and for aggressively regulating consumer data online, and speaks with fluency about the threats posed to young people by climate change and the replacement of human workers by machines. He has pushed back on the left here and there, rejecting the idea of making free college a government goal.More provocatively, Mr. Buttigieg has backed two long-shot proposals to restructure the Supreme Court and abolish the Electoral College. And he has praised, without quite endorsing, ideas for taxing carbon fuel and experimenting with a universal basic income policy, whereby the government would issue cash payments to give citizens a minimum sum to live on.Mr. Buttigieg said he would outline more proposals with time. But he rejected the idea that the Democratic race might hinge on “who has the most elegant policy design.” Because a president cannot execute his plans freely in office, Mr. Buttigieg argued, it would be “inauthentic” to make too many detailed promises.“I actually think I’ve been plenty specific; it’s just that we don’t lead with it,” Mr. Buttigieg said. “I don’t want to drown people in minutiae.”Mr. Buttigieg’s instinct for simplicity and vagueness appears deeply rooted.In 2004, he co-wrote a New York Times column describing research into the platforms of political parties, concluding that winning parties tended to have shorter platforms. And in his final column in his college newspaper, Mr. Buttigieg urged Democrats to focus chiefly on reclaiming terms like “morality” and “compassion” from the right.