DES MOINES, Iowa -- The chant -- "2 cents, 2 cents, 2 cents" -- started in the back of a crowd that packed sidewalks at the Iowa State Fair. Elizabeth Warren, basking in the spontaneous adulation of her proposed wealth tax, prompted roars with her call for the ultra-wealthy to "pitch in 2 cents so everybody gets a chance to make it."
A night before, the Massachusetts senator enjoyed similar treatment when Democrats at a party dinner jumped to their feet -- some beginning to dance -- at the opening bars of Dolly Parton's "9 to 5," the song that would usher Warren on stage.
For someone whose White House ambitions were dismissed by some Democrats earlier this year, Warren's reception in Iowa this weekend was a clear warning sign to other candidates that hers is a campaign to be reckoned with in the state that kicks off the race for the party's nomination.
Warren was one of nearly two dozen candidates who paraded through Iowa this weekend, speaking at the state fair, the annual Wing Ding dinner and a forum on gun control. The sheer volume of visiting contenders signaled a new phase of the campaign, ending the get-to-know-you period and beginning a six-month sprint to the Iowa caucuses.
In that time, the historically large field will winnow, front-runner Joe Biden will be tested more forcefully and a fierce competition will unfold for candidates to be seen as the more viable alternative. They'll be competing for the support of Democratic voters who say their top priority is to land on a nominee who can defeat President Donald Trump.
As the caucuses near, strategists say Warren's ground-level organization -- demonstrated by her large staff and a proven ability to get her supporters to appear at large events like the fair -- is fueling her momentum.
"Elizabeth has a super organization and her campaign is hot," said David Axelrod, who helped run former President Barack Obama's winning Iowa campaign. "But we've seen hot candidates before. August is no guarantee of what happens in February."
As Biden maintains a tenuous lead in polls and Warren gains ground, there's time for ascendant candidates Pete Buttigieg and Kamala Harris to get hot. Bernie Sanders, meanwhile, is still in the top-tier with a devoted following.
Biden and Harris have both boosted their investments in Iowa recently. The former vice president now has 75 full-time staff on the ground and 12 offices throughout the state, a number they're planning to more than double by the caucuses. Harris' team touts 65 staffers and seven offices, and the California senator recently went on the airwaves with an ad focused on her mother and her economic policy.
But Biden's Iowa swing showcased the challenges that lie ahead for him. The visit was marred by a series of gaffes in which he stumbled over his words or seemed to get the dates wrong on major events.
Some longtime Biden supporters worried he's lost some of his spark. Greene County Democratic Party Chair Chris Henning said that, in the past, "I was crazy about him."
"Energy-wise, he looked people in the eye, remembered your name, called your name -- and he's not that Joe Biden anymore," she said.