CEDAR RAPIDS, Iowa — Senators Kamala Harris and Elizabeth Warren took selfies — with each other. Senator Bernie Sanders marched with striking fast-food workers. Mayor Pete Buttigieg of South Bend, Ind., played the blues on an electric keyboard. And former Representative John Delaney brought a team of bagpipers.
The Democratic Party gathering in Iowa on Sunday, the state’s first major event of the 2020 election cycle, had the atmosphere of a circus, and one with a very, very big tent. The 19 presidential candidates in attendance chatted with reporters, gabbed with voters and tried to grab a breakout moment to distinguish themselves in the party’s historically crowded primary field.
A three-hour marathon of speeches by the candidates underscored the stratified reality of the early months of the primary race. There is a set of candidates — at most eight — who consistently break 2 percent in polling nationally and in early voting states, including Iowa.
Then, there is everyone else.
“They’re dividing it into the A group and the B group,” Senator Amy Klobuchar of Minnesota said. “I’m proud to be in the A group.”
Nowhere is that two-tiered race clearer than in Iowa, the state that kicks off the primary contest and where voters expect their candidates to visit early and often.
The candidates tried their best to deliver this weekend, descending on the state for a 48-hour sprint of town-hall-style meetings, meet-and-greets, house parties and, of course, plenty of stump speeches. The 23-person field is large enough to exhaust even those Democrats committed enough to spend a postcard-perfect summer Sunday inside a hotel ballroom along the banks of the Cedar River.
“I’m waiting to see who is leading the race later this year before making up my mind,” said Sue Wagner, a retired schoolteacher from Maquoketa, Iowa. “It’s a little overwhelming right now.”
The convergence of the candidates and their supporters led to an array of only-in-Iowa scenes.
A Cedar Rapids police officer took to his bullhorn to scold Ms. Warren to get off the street. Mr. Buttigieg tossed beanbags with students from Washington. And supporters of former Representative Beto O’Rourke of Texas distributed coupons for free tacos to volunteers and supporters from rival campaigns.
Missing from the action was former Vice President Joseph R. Biden Jr., the leader in the most recent poll of Iowa voters by The Des Moines Register/CNN, who remained in Washington to attend his granddaughter’s high school graduation.
Several candidates offered oblique critiques of Mr. Biden’s record and candidacy. Mr. Sanders, of Vermont, criticized Democrats pursuing a “middle-ground strategy,” an attack he has used before and a clear reference to a Biden adviser who described the former vice president’s climate policy as “middle ground” in an interview last month.
But mostly, they kept their focus on President Trump.
Ms. Harris, of California, said she would “prosecute the case” against Mr. Trump, an argument aimed squarely at Democratic voters’ highest priority — finding a nominee who can defeat the president.
While unseating Mr. Trump was paramount in the minds of Democratic activists, there was also widespread agreement among the candidates that the country needed broader change.
“Beating him will get us out of the valley, but it will not get us to the mountaintop,” Senator Cory Booker of New Jersey said.
Senator Kirsten Gillibrand of New York leaned into the female-centric argument that has guided her campaign, saying: “Now is not the time to be polite. Now is the time to fight like hell!”
And Ms. Warren, a Massachusetts senator who has seen a boost in the polls in recent weeks, argued that Democrats were “ready for big structural change.”
The lack of a clear front-runner in the state has encouraged candidates who have yet to break into the top tier of the race. Presidential campaigns are historically unpredictable, shaped by events both within and beyond the control of the candidates.
At least that is the hope of most of the field.
“There’s very few candidates I think really have any votes nailed down,” Gov. Jay Inslee of Washington said. “It’s a fluid electorate, and you have a lot of folks like myself who are just introducing ourselves to the voters.”
Mr. Biden is set to return to Iowa on Tuesday, when he will begin a two-day campaign swing at the same time that Mr. Trump will be in the state for two events.
While Mr. Biden retains a sizable lead over the rest of the Democratic field, party leaders in Iowa say they have seen little enthusiasm on his behalf.
Some Democrats attribute the strength Mr. Biden and Mr. Sanders are showing in early polling largely to name recognition, arguing that the race will begin to shift over the summer. There is some evidence for that view: The recent Des Moines Register/CNN poll showed support for both men slipping, while Ms. Warren and Mr. Buttigieg saw their numbers rise.
“I really haven’t heard much about Biden up here,” said Laura Hubka, the Democratic Party chairwoman in Howard County, along Iowa’s border with Minnesota. “People don’t want what feels like establishment or ingrained into politics. I know the polls all say Biden has got it by 30 points, but I don’t feel any excitement about his campaign.”
Attendees at campaign events over the weekend emphasized that the coming months would inform their views of which Democrat would be best positioned to defeat Mr. Trump 17 months from now.
“The candidates are drawing enormous crowds, but a lot of the people leaving those events aren’t committing for the candidate,” said former Representative David Nagle, who served as chairman of the Iowa Democratic Party. These early months are a chance for Iowans to look over the candidates closely, he said, “because we don’t want to be wrong.”
While 20 candidates will stand on the stage during the first primary debate this month, many expect the field to winnow over the summer.
And if it does not, the party is likely to force the movement: The Democratic National Committee has announced far stricter qualification measures for the fall debates.
“Once we get to Labor Day we’re going to have two distinct types of campaigns,” said Grant Woodard, a prominent Des Moines lawyer and a former Democratic campaign operative. “We’ll have those that have real organizations in states, and those that don’t and exist to hit up the cattle calls and cable news.”