The Bernie Sanders campaign used two avenues to reach Iowa's youngest voters at tonight's packed rally at the University of Iowa, just two nights before the Iowa caucuses.

First, the opening and closing acts included the band Vampire Weekend, singing along with the Hawkapellas, the university's acapella group, and Mark Foster, the frontman of Foster the People, known for the tune 'Pumped Up Kicks.' 'Hunger Games' actor Josh Hutcherson also joined.

Second, Sanders talked about drugs much to the delight of the college-age crowd.

'Now I know you know nothing about marijuana,' the Vermont senator joked, though warned the young people, 'Stay away from heroin.'

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Talking points: Bernie Sanders spent time talking about heroin and marijuana to a college-age rally gathered on Saturday at the University of Iowa

Face the nation: Democratic presidential candidate Bernie Sanders speaks at the University of Iowa in Iowa City, Iowa, on Saturday

Speech: He also noted how a possession of marijuana charge could really screw up someone's life – while the greedy Wall Street bankers got away with almost destroying the economy

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Besides warning students about a drug that has ravaged communities in his own New England, Sanders had broader points to make when he brought up drugs so early in his speech.

He talked about the black and white divide when it comes to punishment.

He also noted how a possession of marijuana charge could really screw up someone's life – while the greedy Wall Street bankers got away with almost destroying the economy.

'It could hurt your ability to get a job,' he said at one point.

'It should not be a federal crime,' he said at another.

He said legalization should be up to the states.

After the drug discussion, Sanders tossed an array of other liberal meat out into the crowd.

He defended a woman's right to an abortion. He mocked the GOP's use of the term 'family values.'

'What they also mean by family values is our gay brothers and sisters shouldn't have the right to marry,' he said. 'I disagree.'

He got a 'BERNIE' chant for suggesting siphoning the United States off of fossil fuel to combat global warming.

Family: Jane Sanders, right, looks on as her husband as he waves to the crowd during a campaign rally in Iowa City

Greetings: Jane Sanders, left, and her husband, Democratic presidential candidate Sen Bernie Sanders wave during a campaign rally at the University of Iowa

May the odds be ever in your favor: Actor Josh Hutcherson speaks to supporters before Sanders (not seen) greets the crowd at a Students for Bernie Concert and Rally, at the University of Iowa, Iowa Field House

All together: Democratic presidential candidate Sen. Bernie Sanders, I-Vt., second from left, and his wife Jane Sanders sing along to This Land is Your Land with Vampire Weekend

Musician: Lead singer of Vampire Weekend Ezra Koenig performs at the rally for Sanders

Onlookers: A general view shows a crowd of over three thousand people waiting for Sanders during the Students for Bernie Concert and Rally

He promised he would work toward universal health care and free public college tuition.

Sanders has stolen the thunder from Democratic frontrunner Hillary Clinton in recent weeks.

While at one point Iowa was considered an easy Clinton win, Sanders has challenged her and, while a couple points behind, is within the margin of error in several recent polls.

As he makes his final pitch to Hawkeye State voters, he's brought along a number of surrogates deployed throughout Iowa this weekend.

Last night, Foster played a quick pop-up acoustic concert in downtown Des Moines and today went canvassing with other supporters.

Hutcherson is expected to campaign for the senator in Iowa tomorrow.

Actress Susan Sarandon, another celebrity Sanders surrogate, spent time in Iowa earlier this week.

At the rally, filled with students wearing Bernie Sanders t-shirts and purple-lit signs, Cornell West, another popular Sanders surrogate, popped his head up and implored the raucous crowd to join the 'love train.'

Sanders made his trademark pitch.

'This government belongs to us, not just a handful of billionaires,' Sanders said.

And as a finale, he put the message to music, joining his musician surrogates on stage and swaying to 'This Land is My Land.'

Fans: People waited in line for hours to see and hear Sanders speaking to supporters at a Students for Bernie Concert and Rally