BOONE, IOWA — People connected to the Democratic establishment still tend to view the Bernie Sanders campaign with bemusement, incomprehension, or scorn.

They might get a wake-up call when the Iowa caucus results come in on February 1.

A new set of polls indicates that the race in the state — which Hillary Clinton clearly led for all 2015 — is now extremely close. In fact, two of the four polls released so far this month actually put Sanders ahead — they're the first to show him up in months, and seem to suggest the momentum is on his side.

The Sanders message appeals to liberals' hopes and aspirations

Furthermore, the caucuses — which take hours and tend to be low-turnout affairs, and for which voting (for Democrats) is public — can be advantageous to a candidate who has many organized, energetic, and enthusiastic supporters, as Sanders indisputably does.

I spent this past Sunday at three Sanders events in central Iowa. Though the temperature was around zero degrees Fahrenheit outside, all three were packed full with hundreds of people, many of whom seemed to be enthusiastic Sanders supporters. And his message — laser-focused, as ever, on challenging the power of the wealthy and corporations — seemed to resonate with attendees.

Out away from the Washington, DC, bubble — where it's been taken for granted for years that Clinton will win and has to win — liberal-leaning Iowans are seriously thinking about which candidate better represents their values and their ideals, and about which candidate has a better shot at bringing about the major change they feel is still necessary.

And many of them are concluding that Bernie Sanders is that candidate.

Sanders supporters want big change — not small-ball solutions

The pervading sense at Sanders events — both from the candidate's speeches and from my interviews with attendees of all ages — is that something is very wrong with America, and that serious change is required to fix it.

Some Sanders supporters diagnosed the problem as corruption in the political system. "The government is so entrenched in corporate policy, so entrenched in enriching corporations," said April Burch of Boone.

"We've really drifted into the government being for the people with the big money rather than being for and of the people," said Ron Yarnell of Johnston.

Others focused on economic difficulties. At his Boone event, Sanders requested that attendees yell out how much they had in student debt, and a chorus of voices shouted harrowingly high numbers. And in Ankeny, James Bird of Belmond told me he felt he was "no longer part of the middle class." He went on: "I'm possibly being outsourced next year. It's not a big deal for me, because I'm retiring. But my friends are gonna lose their jobs or be forced to take jobs with less benefits and lose their seniority. So I'm pretty much a Bernie supporter!"

And some are just disillusioned with the state of politics, and want something different. "A lot of kids my age, nobody wants to talk about politics; they say it doesn't matter," said Philip Commins, a college student at the Boone event. "But when you vote for Bernie, it does matter. Because he's not saying this stuff to get elected. He's not just parroting what people want to hear."

Sanders has a theory about what Obama did wrong that sounds convincing to a lot of people

Back in 2008, Barack Obama was ideally positioned to capitalize on generalized unhappiness with the status quo. He'd be an obvious change to the incumbent Bush administration, he'd be the first black president, and he could portray Clinton as an adherent to an old and tired style of politics. All of this helped him promise change in a way that sounded credible to liberals.

"Either do this or we become more oligarchic," said one Sanders supporter. "I don't think our democracy has any other choice."

And indeed, most of the older attendees I spoke to said they were Obama supporters in 2008. But they didn't feel like his presidency delivered the change they wanted to see. "I was slightly disappointed," said Bird. "It's been a mixed bag," said Medea Saunders of Ankeny. "He did what he could," said Yarnell.

A key to Sanders in winning over these voters is that he has a very specific theory of what Obama did wrong: He played too much of an inside game focused on Washington wins rather than being an organizer in chief. "The major political, strategic difference I have with Obama," Sanders told me when I profiled him in 2014, "is it’s too late to do anything inside the Beltway. You gotta take your case to the American people, mobilize them, and organize them at the grassroots level in a way that we have never done before."

At a press gaggle after his Marshalltown, Iowa, event on Sunday, I asked Sanders how he could credibly propose so many sweeping new liberal policies that he'd need congressional approval for. And he gave me a similar response outlining his theory of bottom-up change:

The real way that change takes place — and that’s always been the case in this country — is when people on the bottom begin to stand up and say enough is enough. That’s true of the civil rights movement, it is true of the women’s movement, it’s true of the environmental movement, of the gay movement. Millions of people begin to stand up and say, "We need change. Current situations are intolerable." That is when change takes place. So this campaign — the title of this campaign — is "a political revolution." So I believe we can rally the American people, tens of millions of people, to say, "You know what? The United States Congress is going to start listening to us and not to a handful of wealthy campaign contributors." That ultimately is the way that real change takes place. And as president I will be in a very good place to help bring that movement together.

Whether Sanders's theory of change is plausible is certainly up for debate. But what matters to Democrats who feel that the country is on the wrong track is that he has an idea about what could be done differently.

"It may be a quixotic crusade," Yarnell — who's a Sanders supporter — acknowledges. "But we either do this or we become more oligarchic. So I don't think our democracy has any other choice."

Clinton's problem: Her politics don't play into people's ideals

It was probably inevitable that Hillary Clinton — the unmistakable candidate of the Democratic Party establishment, and therefore the candidate of the status quo — wouldn't be able to promise any transformative change.

But not long ago, it appeared to some that Clinton could make a convincing case to the left about how she could be more successful than Obama: namely, that she'd be a tough-as-nails pragmatist, better able to fight and win in grinding political combat.

In a June 2014 piece headlined "How Hillary Won Over the Skeptical Left," Noam Scheiber argued (as he summarized to Vox) that while many liberals still "yearn for someone who wants to change the system," Obama's inability to deliver on his promises of change made these people not "want to get burned again."

In retrospect, the problem with this is that it's not particularly inspiring. If you feel that something is badly wrong with our politics, the argument that Clinton will be an effective steward of a dysfunctional Washington doesn't particularly appeal to people's ideals or hopes.

Furthermore, for people who feel that corporations and the wealthy had far too much power even during the Obama administration, electing someone who's basically proposing to continue the Obama status quo rather than shake things up doesn't really seem sufficient.

Of course, it isn't yet clear which faction of Democrats — those who want major and transformative change, or those who are basically happy with the Obama status quo — is bigger (in Iowa or nationally). What is clear is that Bernie Sanders and his message are exciting a lot of people — and that Hillary Clinton will face a far tougher fight in at least the first two Democratic contests than the establishment ever expected.