While the groups rallied around their candidates in preparation for the crucial Iowa Democratic Party's Jefferson-Jackson Dinner, they did so in dramatically different settings, ones that show the differences in their campaigns.
Clinton supporters started lining up at 7:30 a.m., nine hours before pop star Katy Perry serenaded an estimated 4,000 supporters in a parking lot, according to the campaign.
Students from Iowa State University were first in line, eager to get as close to Perry as possible. Protected by blankets in the blustery Des Moines morning, the students somewhat overlooked the other international figure who graced the stage with Perry: former President Bill Clinton.
Asked whether they were excited to see Bill Clinton, the students shrugged, a departure from the early-morning shrieks they offered to Perry's name.
'Can they hear us across the river?'
It was hard not to know Perry was in town.
The speaker system Clinton's campaign set up blared for most of the afternoon, and when the pop star attended a sound check, nearly all of downtown Des Moines could hear her rendition of "America the Beautiful."
Down the street from the concert, Dan Bram, a Clinton organizer in Iowa, sported a "Left Shark" costume to pump up passersby. The costume is a reference to Perry's Super Bowl performance, when a dancer in a shark costume had trouble keeping up.
Half a mile away, Sanders' supporters were treated to a bit of the concert: Perry's music was, at times, audible to the Iowans backing Sanders.
"We have not been loud enough," one Sanders organizer said from the stage. "I want Katy Perry to hear us!"
Unlike some of his other events across the country -- where thousands come out to see the independent Vermont senator -- Sanders' gathering was not a sizable affair.
The event was not open to the public, and it was less of a rally for Sanders and more of a training session for supporters who were attending the Jefferson-Jackson dinner.
Sanders' aides taught the crowd chants and urged them to be fired up.
"Be loud. Be raucous," they implored.
But throughout the event, it was clear that something else was going on across the river.
"Can they hear us across the river?" bellowed Sanders' emcee. "Get loud as hell one more time!"
But even to some Sanders' supporters, Perry was enough of a draw to get them to not attend the senator's rally.
"We are millennials," said Sandy Barnard, an organizer for Sanders in Chicago who sported a T-shirt with Sanders' profile at Clinton's rally. "I don't know when else I am going to see Katy Perry live for free."
Her friend, Rosie O'Brian, held a sign that read, "Bert+Ernie=Bernie -- Sesame Street for Sanders."
"I didn't realize we were supposed to be at a rally for Bernie right now," O'Brian said with a smile, acknowledging that she wanted to see Perry.
Before the pop star took the stage for four songs, Bill Clinton addressed the crowd, well aware of his role on this day.
"I never have been the warmup act for Katy Perry before," he said. "But I am well aware I am the warmup act."
Perry, sporting a white dress emblazoned with Clinton's campaign logo and wearing the American flag as a cape, serenaded the audience with what has become an unofficial campaign anthem, "Roar."
The Sanders' campaign wasn't far from mind at the event, though. Circling above the stage was a small plane pulling a banner that read "Revolution Starts Now Feel the Bern." The Sanders' campaign paid for the plane and instructed the pilot to fly "up and down the Des Moines River."
The plane, however, never left the few city blocks around the Sanders and Clinton events, and the hum of the engine was clearly audible at lulls in the program at the Perry concert.
Hillary Clinton joined her husband and Perry on stage after the performance.
"Sometimes it is important," Clinton said, "you just have to roar about what we need to fight for."
March to the dinner
In what has become an Iowa Jefferson-Jackson tradition, both Clinton and Sanders supporters marched to the event venue after their respective rallies.
Following a flatbed truck, a mass of Clinton supporters, including high-profile backers such as Iowa Rep. Dave Loebsack, chanted and held signs as they moved up the streets of downtown Des Moines.
Not attending the march: Hillary or Bill Clinton, a break with tradition where candidates escort their supporters to the venue.
Sanders did march from across the river, firing up his raucous supporters by tying his own campaign to the history of the Jefferson-Jackson Dinner march.
Shortly after Clinton's supporters rounded the corner into the dinner shouting, "Hill Yes," Sanders supporters gathered at a different entrance shimmying alongside a Rock Island, Illinois, drill team and its drum line.
Carrying signs that said "The Revolution Starts Now," the crowd chanted "Feel the Bern! Feel the Bern! Feel the Bern!" in unison. When they reached the doors of the Iowa Events Center, the rally leaders held them at the steps for a call-answer chant: "This is what democracy looks like."
"This march will not only get to the event," Sanders said before listing the "great marches" in the United States for civil rights, social justice. "This is a march that will end up in a year when you will join me at the White House."
While Clinton's crowd seemed to disperse on their march to the building, Sanders' supporters stayed in a tight pack, swaying to the drum beats and shouting their candidate's name.
The odd man out
The odd man out in this seemingly two-way race was former Maryland Gov. Martin O'Malley, who rallied his supporters a few blocks from Clinton's concert.
O'Malley's campaign offered a concert of their own. But instead of a multi-platinum musician, O'Malley was his own musical act.
"This song was inspired by Johnny Cash," O'Malley said before breaking into a version of "I've Been Everywhere."
"It's about ... what the hell, it's about running for president of the United States."
The Democratic field narrowed this week when both former Virginia Sen. Jim Webb and former Rhode Island Gov. Lincoln Chafee dropped out.
O'Malley, who has long been in the low single digits, now finds himself as the most likely candidate to get out next. Saturday night's Jefferson-Jackson Dinner is an important moment for the former governor to not only introduce himself to Iowa Democrats, but to prove he is going to make it to February's caucus.