DES MOINES — The pitch from the Democratic presidential hopefuls to Iowans Sunday night was simple: You matter.

Former South Bend Mayor Pete Buttigieg told residents of the Hawkeye State, who hold their first in the nation Democratic caucus Monday evening, how important their “thumb on the scale” is in deciding not only who gets the nomination, but who will ultimately go on to win the presidency. It’s a line he has often used on Nevadans.

“I could tell how seriously you take those choices here in Iowa because over the months that I was working to get knowledge and make our case, when we got to the late summer and the fall, you'd start saying things to me like, ‘Oh, that was a really good speech and a really good message. You are now in my top seven,’” Buttigieg told a crowd of about 2,000 that had packed into the gymnasium at Lincoln High School in Des Moines to hear him speak.

Vermont Sen. Bernie Sanders, speaking later at a Super Bowl watch party across town at Ingersoll Tap, thanked Iowans for the “seriousness in which the people of this state accept their responsibility as the first people who will be voting in the 2020 election.”

“We have done well over 100 events, we have spoken to tens of thousands of people, and I really have been impressed about how serious the people of this state are examining the issues and listening to the candidates and I thank you all very much for that,” Sanders said.

Former Vice President Joe Biden riffed off the assertion by Iowa Sen. Joni Ernst, a Republican, Sunday morning that she was “just pointing out that Iowa has very smart voters” when she said last week that she was “really interested” in what kind of effect the impeachment proceedings would have on the results of Iowa’s Democratic caucus.

"Why don’t you all show Joni Ernst just how smart you are by caucusing for me?" Biden said at a rally at Hiatt Middle School in Des Moines, which was attended by about 1,100.

Massachusetts Sen. Elizabeth Warren had a different adjective for Iowans at a rally at Iowa State University in Ames Sunday afternoon.

“Iowa, you guys are pushy,” Warren said, to laughs from the crowd of about 500. “Now, I mean that in a good way.”

The candidates’ Sunday afternoon swing through the Des Moines area was a coda of sorts. After more than a year of campaigning for the presidency, the first votes in the nominating contest will be cast on Monday.

In other ways, it’s really only the beginning. What happens in Iowa on Monday sets the stage for New Hampshire’s Feb. 11 primary, which could either confirm or buck the results of the Iowa caucus, leaving it up to Nevada on Feb. 22 to either firmly cement a candidate’s front-runner status, serve as a tiebreaker between the victors of the first two nominating contests or buoy a different candidate entirely.

Sanders is polling slightly ahead of Biden ahead in Iowa, with 24.2 percent and 20.2 percent support, respectively, according to the Real Clear Politics' Iowa polling average. Buttigieg comes in third, at 16.4 percent, and Warren fourth, at 15.6 percent. Minnesota Sen. Amy Klobuchar, tech entrepreneur Andrew Yang, billionaire Tom Steyer and Hawaii Rep. Tulsi Gabbard all trail in the single digits.

But what happens in Iowa only happens in Iowa — and it doesn’t stay here, either. It’s a burden that Iowans dutifully bear.

“It is true that Iowans take it very seriously and really put a lot of thought into the process and the candidates,” said David Skidmore, a political science professor at Drake University in Des Moines who was serving as a caucus tour guide for two friends from California and China at the Buttigieg rally on Sunday.

Skidmore, who has lived in Iowa since 1989, also acknowledged the complaints over inequity in the process, allowing a small state where roughly nine in 10 people are white to have an outsize say in the presidential nominating process.

“It’s not fair that Iowa always gets to go first,” Skidmore said. “There’s a point to be argued.”

Several Iowans interviewed at the Biden and Buttigieg rallies Sunday afternoon were, like Skidmore, quick to acknowledge the unfairness of the process, even as they were appreciative of the way in which they have benefitted from it over the last year.

“Obviously we have a lot of access to the candidates,” said Beth Burgmeyer, a 53-year-old from Norwalk. “When I look at the arguments against it — which is, does our demographic really represent the whole country? — I think there are some questions there that it may not.”

Amy Luong, a 23-year old who works in public relations and public affairs in Des Moines, admitted that she’s “kind of a mix” on whether Iowa should go first.

“But the biggest pro for me that Iowa’s first is that it puts us on the map,” Luong said. “We are in the heartland of America. People do not forget about us, so I think that being the first in the nation really brings out what Iowa has to offer. We are here, don’t forget us. We’re here to stay.”

Others were less open to the prospect.

“We always have done it, and I don’t want to be second to New Hampshire,” said Penny Murphy, a 73-year-old retired paralegal from Des Moines. “I want to set the tone.”

Murphy, asked if another non-New Hampshire state were to go first instead, seemed resigned.

“Well, I mean if it goes to that, it goes to that. What can I do about it?” Murphy said.

And it’s not just that they say they take their first in the nation caucus seriously, either. Interviews with Iowans at the rallies reveal the extent to which they deliberate before making their decisions. 

Burgmeyer was deciding between Buttigieg and Sanders; she likes Medicare for all in theory but is worried that it won’t have general election appeal. Luong likes Buttigieg and Biden; Buttigieg “has the brains,” she said, but Biden has the experience.

Skidmore was set on Warren as his number one choice, but was still mulling his second choice pick, should the Massachusetts senator not have enough votes to be considered viable at his caucus site and forcing him to realign in support of someone else: Sanders is too ideologically rigid, Buttigieg is too young, and Biden has been shaky in the debates, he said. Skidmore said he is leaning toward Klobuchar, but is concerned that she isn’t polling well enough nationally.

And, in general, rallygoers said they like the caucus process despite concerns that it remains in inaccessible for some, including those who have to work during caucus hours or struggle to secure childcare in order to participate. 

Nevada Democrats have added four days of early voting to make it easier to caucus, but Iowa Democrats only have satellite caucuses, places where they can caucus during extended hours at a location other than their home precinct.

But the caucus fosters a sense of community that Iowans say they wouldn’t get in an ordinary primary.

“It gives an opportunity to talk to a lot of people about what is it about their candidate that they like and gives you a chance to negotiate,” said Matthew Davis, a 42-year-old from the east side of Des Moines who works in IT for Wells Fargo.

Mary E. Campos, a 90-year-old retired interpreter from Des Moines, can't remember how many times she has caucused in her 84 years of living in Iowa.

"A lot," Campos said. “I think it’s exciting, and I think everyone has a right to it."

But the caucus process is increasingly becoming a relic of the past. Only four states — Iowa, Nevada, North Dakota and Wyoming — will caucus this year for the Democratic presidential nomination after the Democratic National Committee encouraged states to switch to government-run primaries. 

And the caucus tourists, residents of other states who come to Iowa to attend candidate events and observe the caucus, are excited to see how the process will play out this year.

“I think the caucus is truly democratic and I think all the caucus states should go first,” said Marilyn Stewart, a 70-year-old from New Jersey, which won’t vote on a Democratic presidential nominee until June 2. “I wish New Jersey had a caucus where we had an opportunity to speak our minds to our fellow citizens and change their minds. You never know why people have decided for one candidate or another.”