Former Iowa first lady Christie Vilsack has started to tack on at least 15 extra minutes to her grocery store runs. She can barely get through the freezer aisle without neighbors and strangers stopping her to offer their thoughts on Iowa’s looming Feb. 3 caucuses. They pick her brain about contenders’ strategies, and worry aloud that President Donald Trump may be coasting toward an easy re-election.

“They say, ‘These are my top three today. Maybe not next week, but today,’” says Vilsack, who is married to former Governor and ex-Agriculture Secretary Tom Vilsack. The couple is backing Joe Biden in the upcoming caucuses, and the Vilsacks spent their weekend on the former Vice President’s pre-Christmas bus tour of the state. “They’re not going to make up their mind until they walk in the door [on the night of the caucuses],” Christie Vilsack tells TIME.

Such is the state of affairs in late December in Iowa, which every four years leads off the nominating calendar with its caucuses. The contests are a test of candidates’ ability to organize and execute a complicated system rooted in arcane rules and, fairly or not, they often determine leaders’ viability and prompt a number of contenders to bow out to save future embarrassments.

Six weeks ahead of the caucuses, the frontrunners in Iowa are Biden, South Bend, Ind., Mayor Pete Buttigieg, and Senators Elizabeth Warren of Massachusetts and Bernie Sanders of Vermont. Chasing them are Senators Cory Booker of New Jersey and Amy Klobuchar of Minnesota, both sleepers who have made the effort to build impressive political machines in the state but whose numbers do not correspond with their elbow grease. Come Feb. 3, any candidate who fails to snag 15% support at each caucus site will be shut-out.

Caucus-goers are still shopping for a preferred candidate. Iowans famously make their decisions late and, given caucus locations’ traditions of real-time lobbying of Iowans in school classrooms and church halls, nothing is certain except uncertainty. Biden has long been the front-runner in the state, but his advantages may be fragile, and many activists are inspired by the sweeping structural changes promised by Warren and Sanders, as well as the generational shift that Buttigieg offers. In a non-scientific survey of three dozen Iowans over two days of Biden rallies, there remains a remarkable level of fluidity that suggests Iowa remains a jump ball, which is why all eyes will return to the state as soon as the holidays pass.

“I really liked Bernie Sanders [four years ago]. Now? I’m not even sure who I’m caucusing for,” 38-year-old Sara Johnson told TIME at Biden’s Dec. 21 rally in Ottumwa. She said her choice will likely come down to Biden or Warren. “We need someone who is electable more than anything else.”

The question of electability has become one of the defining concerns of the 2020 Democratic race. Democrats consistently say in polls that a candidate’s ability to defeat Trump is more important than her or his ideology. Biden, who continues to hold steady atop of the Democratic field nationally, had made electability his main pitch to Iowans, and the issue came up repeatedly in conversations with Iowa Democrats who attended Biden’s pre-Christmas events.

“I’m looking for a Not Trump,” said 50-year-old Laura McLean of Atlantic, Iowa, where Biden began his Dec. 22 with church services and a rally. She listened to Biden and found his argument about restoring U.S. standing in the world compelling, but added “there were a few places where he was wandering.”

Graphic artist Lia Marsh, who also attended the rally in Atlantic, said Biden’s pitch against Trump landed firmly with her and she “probably” will caucus for Biden. Like so many Iowans, she’s not necessarily looking for an ideological match as much as someone who can make Trump a one-termer. “I think he’s the only one who can win,” the 30-year-old said of Biden.

A day earlier, in Ottumwa, 71-year-old retiree educator Linda Perry said she and her husband understand the appeal of some of the candidates, but they are not convinced anyone but Biden can edge out Trump. “We are ready for someone who is a gentleman to represent us. The others are good but winning is up in the air with them. We can’t risk that,” she said on Dec. 21.

That’s not to say Biden has a lock on anything yet. He remains in a tight race in Iowa against others who have spent far more time in the state so far this year, and Biden did not win the state in either of his two previous bids for the nomination. “I’m not convinced we have a frontrunner yet,” says Dana Kunze, a 53-year-old art teacher and the chairman of his local caucus in Griswold, Iowa. “Joe Biden is the national frontrunner, but Iowa is Iowa, and we are used to a certain level of attention,” he said on Dec. 22.

That hold-out instinct is typical in Iowa, where many Democrats see their role as the first vetting any of the candidates receive. In many ways, Iowa is an early gatekeeper for the rest of the country. While the state’s demographics don’t reflect the country’s diversity — and certainly not the Democratic Party’s — it does serve as a check. Candidates have to meet voters face-to-face, and that in-person, retail-style politics is why lesser-known candidates often have a chance here, and why national frontrunners are not guaranteed of anything.

Consider how Dec. 22 unfolded in Perry, Iowa, a small town where Tyson Foods operates a pork processing plant. During the afternoon, Buttigieg visited and made his pitch to voters. In the evening, it was Biden’s motorcade that rolled into town to meet many of the same voters, like 60-year-old librarian Jill Book. “I’m like everyone else. I like all of the candidates, but I’m on the fence,” she says. Warren is her top choice, with Biden and Buttigieg tied behind, but she’s still shopping. “I wish we had a candidate who appeals to white, working-class voters and millennials,” she says. “Mayor Pete said all of the right things, but I wish he’d follow Biden’s lead in not going after any of the others personally — because we cannot have a damaged nominee.”

Among Democrats at Biden’s rallies, the specter of 2016 of the brutal Hillary Clinton-Sanders battle still looms large. Many voters say they don’t want a repeat of that intra-party feud that left many Sanders supporters sour and on the sidelines after Clinton won the nomination.

As Biden wrapped up his bus tour on Dec. 22, Tom Vilsack, Christie Vilsack’s husband, made a pitch to voters about Biden’s strength in the polls in Georgia, North Carolina, Pennsylvania, Wisconsin, Iowa, Texas, Nevada and Arizona. They are all states central to what Democrats generally see as their litmus test for victory up and down the ballot next year.

“There is only one candidate in this race today that is either beating Donald Trump by a significant margin or is tied with him in each and every one of those states and that candidate is here tonight: Joe Biden,” Vilsack said. “He’s the one candidate in this race who can win.”

That hit home for 64-year-old Kent Scheib. “Some people get locked into who they like. They need to lock into who can win,” says the retired farmer from Perry, who hours earlier also attended the Buttigieg event. Scheib is still trying to decide between the pair. “I like everyone,” he says. “But electability is everything.”

Which is why, as Biden’s campaign pivots to its final chapter leading into Iowa, his team is confident that it has a shot — if not at winning Iowa, than at least the nomination after a protracted fight. While few in Biden’s crowds match the passion of a Sanders or Warren audience, there’s a quiet pragmatism to them. And that may just be sufficient, coupled with antipathy among Democrats toward Trump, to start building a delegate firewall, starting in Iowa.

Get our Politics Newsletter. The headlines out of Washington never seem to slow. Subscribe to The D.C. Brief to make sense of what matters most. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Philip Elliott at philip.elliott@time.com.