DES MOINES, Iowa—Michael Moore got to break the news on Saturday morning.

“Let me get right to it and tell you, if you didn’t wake up and see the good news this morning: the New York Times poll, for Bernie, ahead in Iowa,” the filmmaker, surrogating for a D.C.-stranded Bernie Sanders during a town hall at the University of Northern Iowa in Cedar Falls, said to a loud round of applause. “And I mean way ahead, way ahead.” As the applause escalated to election night victory levels, Moore had to dial it back.

“All right, all right, no end zone dancing on the second yard line, right?” Moore said. “We’ve seen what happens when you do that. This isn’t over yet.”

It was nine days until the Iowa caucus, and the data dump from numerous pollsters that weekend showed a Sanders surge, a phenomenon reflected in national and New Hampshire polls as well. That energy was apparent in the campaign’s events throughout the day on Saturday, which culminated with an evening rally in Ames where about 1,000 people watched Sanders, finally able to get away from impeachment trial duty, in the main auditorium while another 400 milled about in the gymnasium serving as an overflow room. If the Sanders campaign is having any problem in Iowa, it’s the high expectations it has created: The state, in the final sprint to the finish line, is becoming Sanders’ to lose.

Sanders’ nearest rival in the Iowa polling average is Joe Biden. And though Sanders and Biden rarely take direct snipes at each other during events, the other’s campaign, and the other’s theory of change, looms over each candidate’s events. On the surface, the homestretch debate between Sanders and Biden is one over perceived electability, and each candidate and his respective surrogates have contrasting cases to make for their viability. But at the core, the dispute between the two is about fear. The possibility of Donald Trump winning another four years as president is either the reason why the party can’t take the risk on a nominee like Sanders, or the reason why it must.

The Biden campaign has stopped being subtle, to the extent that it ever was, about positioning him as the necessary person to stop Trump. Over the weekend, the campaign began running a new television ad in Iowa called “Threat.” It’s a direct appeal to Biden’s ability to beat Trump, displaying graphics of nine separate polls showing him doing that nationally and in swing states. Biden is emphasizing not just his head-to-head strength against Trump, but his pull at the top of the ticket.

On the campaign trail over the weekend, Biden campaigned with a carefully selected group of surrogates: Iowa Reps. Cindy Axne and Abby Finkenauer, Texas Rep. Colin Allred, and Pennsylvania Rep. Chrissy Houlahan. All four are freshman “front-liners” who flipped seats for Democrats last cycle, and all four spoke about how they need Biden not just to win the presidency, but to hold the House and flip the Senate.

The transactional nature of their pitches was refreshingly direct. “We need a leader at the top of the ticket who understands the importance of moving our country in the right direction, but also somebody who will ensure … Democrats, like Abby and I, will get reelected, and that we’re able to grow the majority,” Axne said at an ironworkers’ union event in Des Moines Sunday morning.

Allred, meanwhile, at a later event in Marshalltown, told the hundred or so attendees that “Joe Biden puts Texas in play,” and only Joe Biden puts Texas in play.

“I know people in my community who are looking for another option,” Allred, who represents northern Dallas suburbs, said. “And Joe Biden is the only person running for president who will get their vote. So we need you to send him [to] us.” While Allred focused on the tantalizing prospect of Biden expanding the map, Houlahan reminded voters that Biden, and only Biden, can reconstruct the Rust Belt “blue wall” that Donald Trump smashed through in 2016.

“The eyes of the world are on you,” Allred told the Iowans, assembled in a barn on the Central Iowa Fairgrounds.

This stuff works. Many of the Iowa caucusgoers I spoke to at events talked about feeling more pressure this cycle, with another four years of President Donald Trump on the line, to get it right than they have in cycles past. Some, like Kristin Tracy of Des Moines, who’s between Biden and Amy Klobuchar, are thinking beyond their interests as Iowans and hoping to propel the candidate with the best chance nationally. “It’s a big pressure,” Tracy said, “to be mindful of representing the Democratic Party in general, and picking somebody that everybody can get behind, and not just all the white people in Iowa.”

Other Biden supporters think about their Republican relatives. Susan Judkins, a Biden supporter who serves on the City Council of Clive, a Des Moines suburb, grew up in the rural town of Vinton, Iowa, and spoke about how registered Republican members of her family back home are looking at the Democratic primary.

“When they hear candidates talking about programs that seem very expensive—there isn’t that much income difference between professionals or businessmen and individuals working for them” in Vinton, Judkins told me at an event in Des Moines. “And they all look around to imagine who pays for programs like that, and they figure that means them.” She appreciated how Biden, in contrast to certain candidates, “has expressed an understanding of that, and a willingness to stake out a position that might not be as popular on a front end.”

Biden’s events draw older, more staid crowds. They’re more intimate, and that’s not just a euphemism for smaller. Maybe he’s lost a step since his prime, but Biden is still a world-class charmer who can convince people he’s never met that they’ve known each other their whole lives. When one woman, in Marshalltown, told Biden after the rally that her daughter reluctantly missed the event because she had to work, Biden had her call up her daughter, and the two had a conversation on the phone. (It’s a trick he’s likely used since the day cellphones were invented. It works.) He has a calming effect for those who just want to be calmed and who want to believe that the country isn’t broken—it just has the wrong guy leading it.

“I’m 66, so I kind of lived through the era that Joe’s talking about,” Ann Harms told me at the end of Biden’s event in Marshalltown, speaking about Biden’s pitch that he can bring the country back together. She understood why young people are flocking toward more confrontational candidates, like Sanders and Warren. It’s just not for her.

“I know that [young people] are really needing the help for college tuition and health care and things like that,” she said. “But I guess I’m such a traditionalist. I have enough faith in our democracy and our government that, if we have the right person leading us, that we can meet those challenges and still bring us all the help we need.”

Bernie Sanders does not grab people’s cellphones to call their daughters. He preaches the gospel of political revolution, impersonally, to overflowing crowds, imploring them to imagine something better. The atmosphere, especially during warmup acts, is often indistinguishable from protests outside the U.S. Capitol. At the University of Iowa on Friday night, in Iowa City, attendees participated in a hand-squeezing exercise with their neighbors followed by a call and response; there was an acoustic rendition of Bob Marley’s “Redemption Song.” The following night, in Ames, there was a moment to recognize that the territory “now known as Iowa” used to be Native American land, and a call for land reparations.

With Sanders mired in Washington for Trump’s impeachment trial, it was up to two surrogates—Michael Moore and Rep. Alexandria Ocasio-Cortez—to carry the load on Friday and the first half of Saturday. They did not struggle to draw crowds. One attendee at a town hall in Cedar Falls on Saturday afternoon told me that he was choosing between Biden and Buttigieg. So why was he there?

“I’m really excited to see AOC,” he said.

Ocasio-Cortez does not spit fire at rallies. She tells stories and tries to get the audience’s minds working. She told one story about how she couldn’t afford to get a blood test she needed, and when the doctor asked what her job was, she said, “I’m running for Congress.” She gives behind-the-scenes looks at how Congress works, like how prospective congressional candidates are told not to bother running if they can’t raise $300,000 immediately, or how her more cautious colleagues tell her, privately, that they don’t oppose single-payer health care per se. They just say that if Democrats run on it, “we will lose.”

“It’s not that we can’t,” Ocasio-Cortez said in Iowa City. “It’s that we’re scared.”

And Sanders supporters hate the arguments made against their candidate on electability grounds, which have been around for five years and are reaching a new pitch as Sanders rises in the polls. “I remember 2016, everybody said, ‘We’ve got to put Hillary in,’ ” Mel Underbakke, from Decorah, told me in Cedar Falls. “And look where we are now. I think if Biden gets in, I think Trump will win, and I think it will be an easy win.”

Sanders supporters, and the Sanders campaign, argue that Joe Biden doesn’t have any energy behind him, and that he’s too much of an establishment politician—too connected to elites and wealthy donors—to marshal the populist energy necessary to win over the “working people” lured away by Trump. And with Sanders surging, so are fears about how the Democratic Party won’t allow him to be the nominee.

“My biggest concern is the Democratic Party will not give it to him. It’s like they don’t want to give it to him. And I’m afraid that they’re just going to give it to Biden,” Alyce Shearer said in Marshalltown. “I feel like they promised Joe, We’re behind you, we got you.”

Sanders is comfortable stoking certain fears about the establishment himself. At his rally in Ames on Saturday night, after he had returned quickly on a chartered flight from D.C., he spoke about how nervous the establishment was getting as they saw his rise in the polls (correct). Popping into the overflow room in Ames to address the crowd there, before giving a much lengthier speech to the main crowd in the auditorium, Sanders laid out his path to securing the nomination, whether party officials like it or not.

“I believe, with your help, we have an excellent chance to win here in Iowa,” Sanders said. “And if we win here in Iowa, I believe we have a very good chance to win in New Hampshire. I think we’re going to win in Nevada, I think we’re going to win in California.” (Note that he skipped saying anything about South Carolina.) “And I think we’re going to win in a number of other states and capture the Democratic nomination.”

Sanders despises political pundits. But he was speaking in the same terms the horse race observers have been using. This particular cascade of events he described—positioning himself to win the first three early states, giving his campaign momentum that not even Biden’s barricades in South Carolina can halt—is the exact scenario that politics handicappers are looking to see if he can pull off, and the exact scenario that is giving mainstream Democratic officials nightmares. None of that can happen, though, if he can’t close the deal in Iowa, and he can’t close the deal if voters listen to the ever-louder arguments about the risks of nominating Sanders in the next week.

Polls show that Democratic primary voters still think Biden has the better chance to beat Trump than Sanders. It will be hard for Sanders to flip that pragmatic belief. It would go against too many years of received knowledge for a majority of voters to believe that the socialist could be a better general election candidate than Uncle Joe. What Sanders and his surrogates have to do, instead, is convince people that he’s worth taking the chance on, and that it’s all right to want more than just to beat Donald Trump. If the simple slogan of “hope” hadn’t been so co-opted by a certain presidential candidate in 2008, it would be a useful one for Sanders now.

At the Iowa City rally on Friday, Michael Moore was joking about how nervous Democrats once were at the thought of a candidate with the middle name “Hussein,” as though voters would have convulsions upon seeing it in the ballot booth.

“We only win,” Moore said, “when we take risks.”