“The campaign is moving so fast the infrastructure can’t keep up,” Sanders confesses. “It sometimes reminds me of a military campaign, where the front line of the army is moving faster than the supply chain.” Since Berniemania began this summer, he and a small band of aides have been scrambling to turn it to their advantage.

You don’t often hear politicians admit that they didn’t expect to catch on. But Sanders and his team have a bracing habit of saying things politicians and their aides are not supposed to say—a minor violation of norms that reminds you how accustomed we are to being lied to in politics.

Another basic tenet of campaign spin is that consultants must never admit their candidate isn’t totally perfect, but Sanders’s people apparently missed that lesson as well.

“I give him advice—not always advice that he follows,” says Tad Devine, the veteran Democratic consultant, a former adviser to Al Gore and John Kerry, who is Sanders’s top strategist. “He is not interested in the niceties of appearance and hairdo.”

Sanders’s communications director, Michael Briggs, adds: “He goes on for an hour-long, eat-your-spinach kind of speeches. And people are clapping for it!”

In that spirit of radical honesty, I am not going to tell you now that Sanders “just might give Hillary Clinton the shock of her life,” as is customary in these kinds of stories. Sanders is drawing a steady quarter-to-a-third of the vote in Iowa and New Hampshire, pulling within 10 points of Clinton in some New Hampshire polls. Some Clinton aides have begun floating the notion that she could lose one or both of those early-voting states, though this seems like an attempt to lower expectations. But Clinton is still the favorite of Democratic voters nationally by nearly 30 points. She has the money, she has the endorsements from the party elite, and she has the massive teams of staff and advisers.

But Bernie Sanders has one thing Hillary Clinton doesn’t: an ideology.

When Sanders set out to run, he tells me, his main fear was that doing so might prove harmful to his ideas. “If I failed, if it was a bad campaign, if we didn’t get many votes—fine, I can live with that,” he says. Sanders is leaning back on a couch, his leg propped up on a table, squinting through his unfashionable glasses into the middle distance.

“But the ideas that I am talking about—if the campaign did badly, then it would give the establishment the opportunity to say, See, Sanders ran on a platform calling for single-payer national health-care system, and he did really poorly,” he continues. “He ran on a platform calling for the creation of millions of jobs through rebuilding the infrastructure—nobody really supported him. He talked about income and wealth inequality; it didn’t go anyplace. Those aren’t really good ideas!”

They are like babies to him, fragile and cherished, these ideas. Sanders almost cringes at the thought that they could suffer. “What worried me was not what happens to me personally if I failed—what worries me is what happens to these ideas,” he says. “Well. When you have 10,000 people coming out to a meeting in support of these ideas, then people say, Hmm, maybe these ideas have some resonance.”