On Jan. 14, ahead of the Democratic primary debate at Drake University in Des Moines, the Olmsted Center Starbucks on Drake's campus was overrun with figures in green T-shirts — not the deep green of the coffee shop logo, but a brighter shade that Sen. Amy Klobuchar (D-Minn.) has claimed for her presidential bid. As of about 5 p.m., the swarm inside Starbucks spilled out of Olmsted, a student hub, and stretched all the way to a rally a few blocks away on a snowy tract of grass.

Among the Klobuchar supporters were Richard Jennis, 25, and Cody French, 26, two friends from Excelsior, Minn., who had taken a 3½ -hour bus ride from the Twin Cities to be there. French said he has been active in politics but not in presidential races until now. “After Trump got elected I figured I couldn’t afford to sit on the sidelines anymore,” he said. Jennis thinks his home-state senator can defeat Trump because she boasts “a lot of appeal in the states that were essential in the 2016 election ... like Minnesota, Iowa, Wisconsin, Michigan and other Rust Belt states.”

But rather than try to score tickets to be in the debate audience when Klobuchar joined the five other candidates onstage that night, Jennis and French had come for another presidential debate ritual: the official campaign watch party. These gatherings are quasi pep rallies, often with campaign officials or surrogates as guest speakers and some sort of instruction for organizers. And there’s always food. Within those parameters, each campaign’s shindig is distinct in turnout, makeup, style and demeanor.

In Des Moines, watch parties for three of the six candidates took place on separate floors of the Olmsted Center. Klobuchar’s campaign took the top floor, the campaign of Sen. Elizabeth Warren (D-Mass.) took the first, and supporters of former South Bend, Ind., mayor Pete Buttigieg occupied the basement theater space. Former vice president Joe Biden, Sen. Bernie Sanders (I-Vt.) and billionaire activist Tom Steyer held their watch parties in another part of town.

Warren and Buttigieg’s teams soon arrived at Olmsted. But they were far smaller in number than Klobuchar’s army of 400. (The campaign had sent three busloads from Minnesota.) Just prior to the start of the debate, a few of Buttigieg’s yellow-shirted supporters were still outside, dancing awkwardly to “High Hopes” by Panic! at the Disco, which blared from a speaker. Then the front doors swung open and former presidential candidate Julián Castro rushed inside; he was expected at a pre-debate “strategy session” for Warren organizers.

On my way from the Klobuchar rally to her watch party, I passed an Infowars reporter who was heckling Anderson Cooper as the CNN anchor walked to the auditorium for the debate. After a while, the Infowars guy gave up and disappeared inside the Olmsted Starbucks.

Just before 8 p.m., I headed to the Sanders watch party three miles away, across the Des Moines River in the city's East Village, an artsy historic district that BuzzFeed once dubbed "the closest thing to Brooklyn that Iowa has ever seen." As we pulled up, my Uber driver noted that Curate, the 6,000-square-foot gallery and event space where the party was taking place, was "very swank."

It was swank, and packed with a diverse crowd of about 200 that skewed young — lots of beards, both kempt and unkempt, and beanies galore. The Domino’s pizza was free, but drinks at the bar were not. (Attendees mostly scorned the Bud Light and Michelob for Founders’ All Day IPA and Exile, a local brew.) “I cannot miss a second of this,” one woman told her friend as the debate got underway.

After loud cheers for Sanders, there were groans for Biden when he mentioned his closeness with Barack Obama and defended his vote to invade Iraq. Then came the allegation that Sanders once told Warren a woman couldn’t win the presidency. I’d left by then, but according to a Washington Post account of the party, his supporters cheered when he denied having made the comment, then gasped when Warren doubled down, “stunned at the collapse of what they viewed as an unspoken alliance.” For the rest of the night, many “groaned or even booed” Warren.

My next stop was Steyer’s party in the quiet neighborhood of Beaverdale. The billionaire’s gathering was a smaller, humbler affair than the democratic socialist’s. About 20 people, mostly white and male, huddled in his Des Moines field office. Barbecue, potato salad and soda bottles sat on blue plastic tablecloths along with paper plates and red Solo cups.

In two Iowa polls before the debate, Steyer’s support was in the low single digits, while two Fox News polls released Jan. 10 had him at 15 percent in South Carolina and 12 percent in Nevada. That was enough for his last-minute inclusion in the debate — but, as his watch party attendees in Des Moines nodded and cheered politely, they seemed only to reinforce a sense that his momentum was elsewhere.

Back in the basement of Olmsted, Kasey Springsteen sat among 100 or so Buttigieg supporters, glued to the television. A Drake junior, she recently decided to caucus for the former mayor. "Not having that national recognition coming into this state can be really hard," she said. "And Iowa-born and -bred, we're not exactly the most accepting to newcomers, but I've just been really impressed with how he's been able to mobilize and inspire."

The debate was winding down as I reached the ground floor, where Warren’s faithful occupied an awkwardly shaped space. They looked similar to the Buttigieg supporters in age (most were young) and dress, but they were significantly more diverse. I didn’t see anyone boo Sanders. According to news accounts, when Warren pointed out that the women onstage had won more of their races than the men, applause broke out, followed by chants of “Warren, Warren.”

Supporters of the various presidential hopefuls began filing outside around 10 p.m., after the debate ended. (I never made it to Biden’s event.) A chill had swept in; the temperature wouldn’t break 30 degrees the next day. Some faced a long ride home. Still, no matter how many times they’d seen the candidates squabble over the potential cost of Medicare-for-all or zing one another over impolitic comments and visits to wine caves, these die-hards sounded ready for more.

Scott Nover is a writer in Washington.