Backstage at Bernie Sanders' rock star party in Iowa

Josh Hutcherson, Vampire Weekend party for Bernie
Josh Hutcherson, Vampire Weekend party for Bernie

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  • Bernie Sanders drew his largest crowd in Iowa on Saturday, two days before the caucuses
  • But he had a little help from his friends

(CNN)Bernie Sanders drew his largest crowd in Iowa on Saturday, two days before the caucuses, but he had a little help from his friends.

Speaking on campus at the University of Iowa, the Sanders campaign assembled a star line-up of celebrities and artists -- particularly geared toward the Millennial sort -- to perform alongside him while he gave his final Hawkeye State pitch: Actor Josh Hutcherson, who played Peeta Mellark in "The Hunger Games," Vampire Weekend frontman Ezra Koenig, the band Foster the People and comedy duo The Lucas Brothers.
An estimated 4,000 people flocked to this college town to attend the rally, some waiting up to 12 hours to be the first in a line that wrapped several blocks across campus.
    Sanders is expected to have a strong showing on caucus night in cities with large concentrations of young people, many who say find him more authentic than other candidates in the race.
    "I see a consistency in him that's rare in most human beings and politicians," said Koenig, who performed acoustic versions of Vampire Weekend songs Saturday and a duet of "This Land Is Your Land" with Sanders on stage.
    "I think there's something so cool about Bernie running as a Democrat, a guy who was the only independent in the House for a long time, the only independent in the Senate. A guy who comes from an outside structure and kind of bringing that to the Democratic Party, there's something so much more exciting than someone that comes from within," Koenig said.
    Sanders' challenge, however, is to compel the students to show up to Monday's caucuses, a process that requires several hours of commitment. And while he may do well in college towns, his success here will hinge on whether he can draw large numbers of caucus-goers beyond college towns.
    A Des Moines Register/Bloomberg Politics Iowa Poll released Saturday night showed evidence that Monday's contest could be very close between Clinton and Sanders, which Clinton leading by just three percentage points, a number within the survey's margin of error.
    Watch the video above for exclusive backstage interviews with Sanders' celebrity supporters.