Iowa’s most famous millennial, Taylor Gipple, is a twenty-two-year-old Des Moines native and recent college graduate who, as of the start of this year, had never voted in an election, let alone participated in the ethanol-and-circuses spectacle of his home state’s caucuses. Then he discovered Bernie Sanders, and, after a whirlwind bout of YouTubing videos of the senator speaking in favor of gay rights all the way back in the nineties, railing against the Iraq War, and decrying the campaign-finance system, Gipple’s conversion was complete. At CNN’s Iowa Democratic Town Hall, Gipple rose to pledge his allegiance to Sanders before Hillary Clinton, a moment that quickly became a political meme. “It feels like there’s a lot of young people like myself who are very passionate supporters of Bernie Sanders, and I just don’t see the same enthusiasm from younger people for you,” he said, as Hillary, shown in split-screen, assumed the tight-lipped wince of a “Bachelor” contestant mid-rejection. “In fact, I’ve heard from quite a few people my age that they think you’re dishonest.”

Gipple is right, as the Iowa caucuses made clear: there are a lot of young people who mistrust Hillary and passionately support Bernie. Last night, eighty-four per cent of Democratic voters under the age of thirty voted for Bernie, while Hillary won two-thirds of her and Sanders’s own sixty-five-plus cohort. The truest young Bernie believers are under twenty-five, according to a survey of the political attitudes of millennials published in December by the Harvard Institute of Politics, with college students the truest of the true. Bernie would not be pressing Hillary without the support of the youth of America, a fact that I—a voter north of twenty-five, south of thirty—have pondered over the past few weeks with increasing perplexity.

The demographic so often maligned as Generation Selfie is rallying behind the candidate who has far and away the most shambolic presentation of anyone on either side of this crazy race? A fist-shaker and haranguer who makes the “Yakety Yak” dad look chill, the nutty great-uncle at the Seder table who insists on debating the morality of the Ten Plagues while everyone else is dying to just eat already: Really? That’s the guy with the youth vote?

Bernie’s attractiveness as a candidate relies on the premise of purity—a political value as ancient as politics itself. In contemporary American politics, purity is the domain of independents, who can claim to resist the nefarious influences that representatives from the major parties must necessarily fall prey to, including the influence of the parties themselves—their ingrained culture, their policy platforms, their network of donors, even their traditional voter base.

It’s no coincidence that Sanders and Trump, the two current candidates who, as the Times pointed out this weekend, have electrified voters by invoking their own political purity in the form of their shared disdain for Super PACs and conventional party platforms, are both independents, or that each employs a rhetoric of cleansing the country rather than merely improving it. For Trump, Muslims, Mexicans, immigrants, and refugees of all kinds are the taint; for Sanders, it’s the big banks. That neither candidate has a chance of getting his proposals on those fronts through Congress only strengthens their claim to incorruptibility—though, of course, neither is so pure as to actually run as an independent and renounce the power that winning the nomination of one of the major parties would bring. (Though it’s true that Trump seemed somewhat relieved by his second-place finish in Iowa, the better to get on with his plans for luxury-farm developments.)

So purity, a highly useful principle to make use of while running for office, is all but useless to politicians who actually arrive there, and the voters least likely to see that are young ones. The belief in the possibility of true purity might be a delusion for most voters, but it’s a privilege of youth, the province of people for whom the thrill of theory hasn’t yet given way to the comparative disappointment of practice. It’s a rite of passage into political adulthood, when the contours of the world seem sharper than they may ever be again, and the notion of the correspondence between the politician one votes for and the one who arrives in office is still intact—that moment of “very heaven,” as Wordsworth’s famous line about witnessing the start of the French Revolution as a young man has it.

The college students and recent graduates who fervently support Bernie are enjoying their own moment of heaven, inevitably brief. I say this in spiritual solidarity. My own phase of very-heaven fell during the first campaign of Barack Obama, another candidate whose supporters touted him as entirely pure, only to eviscerate him when that premise disintegrated under the pressure of actual politics, and so it’s impossible not to see the fervor of young support for Bernie as a reaction, in some part, against Obama the Firebrand turned Obama the Moderate.

But Obama as a candidate may be as close as many of us will ever come to a twenty-something’s ideal politician—the sheer force of that fluid, academically honed intelligence! The nuance and honesty of the race speech! The dancing!—and a comparison of the two on that count yields something very odd. Bernie’s crankiness to Obama’s cool, his age to Obama’s freshness, his nagging to Obama’s rhetorical deftness, his hokiness to Obama’s humor, his gout to Obama’s jump shot: all make for a strangely conservative vision of a youth idol. (Then there’s the awkward fact of the most diverse generation of voters in the country’s history rallying behind another white guy.) I sense a whiff of historical fetishism in the young love for Bernie, a yearning for an imaginary time of simpler, more straightforward politics that aligns with other millennial tendencies toward false nostalgia for past purity, in fashion or food, for instance. The obsession with the banks and the bailout is itself phrased in weirdly retro terms, the stuff of an invitation to a 2008-election theme party. As my colleague Ben Wallace-Wells points out, we voters under thirty have come of political age during the economic recovery under President Obama. When I graduated from college, unemployment was close to ten per cent; it’s now at five. Sanders’s attention to socioeconomic justice is stirring and necessary, but when his campaign tweets that it’s “high time we stopped bailing out Wall Street and started repairing Main Street,” you have to wonder why his youngest supporters, so attuned to staleness in all things cultural, are letting him get away with political rhetoric that would have seemed old even in 2012.

One risk that comes with all the celebration of Bernie’s intransigence on the issues is the implication that any change in political opinion or action is automatically corrupt. As Taylor Gipple made evident, the suspicion that political compromise is inherently venal is at the root of the grievances that so many of Bernie’s young supporters harbor against Hillary, whose long record bears the kind of battle scars that are easily dodged by an independent senator from Vermont. But rethinking one’s position, or tactics, or point of view, can be a far greater mark of integrity than any purist’s staunch refusal to yield, in politics as in anything else. One conclusion to draw from Obama’s Presidency is how necessary the right proportion of flexibility and resolve is for the job, and what a significant liability the insistence on purity can be when it comes to the actual business of governing.

The intragenerational gap asserts itself with the speed of Moore’s Law these days, which might be why a micro-split was in evidence in the Harvard millennials study, with twenty-five- to twenty-nine year-old Democrats—the portion of the age bracket that has voted before, and witnessed the election-to-elected transformation firsthand—preferring Hillary, a candidate whom many believe to be as impure as they come. “Seasoned,” her supporters might say. What will my twenty-something counterparts in New Hampshire make of that? “They throw all this stuff at me, and I’m still standing,” Hillary told Gipple, before reminding him that the ultimate point is to have the Party come together to win in November, a point that she repeated in her Iowa narrow-victory speech. For that to happen, a lot of young Democrats may have to learn how to embrace compromise.