One of the most telling statistics from Monday’s Iowa caucuses was the margin with which Bernie Sanders beat Hillary Clinton among young caucus goers.

Entrance polls found that voters ages 17 to 29 overwhelmingly preferred the 74-year-old socialist candidate, 84 percent to 14 percent.

An analysis by the Center for Information and Research on Civic Learning found that young people made up 15% of total caucus-goers, which, though down from 2008, still represented a high youth turnout.

“To get young people to vote in a primary takes a lot of effort,” said David Redlawsk, a professor of political science at Rutgers University, who spent the last six months in Iowa studying the campaign.

Sanders put a lot of energy into mobilizing college students. He hosted more events on college campuses than Hillary Clinton and advocated policy proposals to make public colleges free.

Young people care deeply about inequality, an issue Sanders has made central to his campaign, and tend to prefer candidates who share their values instead of candidates with experience, said Kei Kawashima-Ginsberg, head of the Center for Information and Research on Civic Learning at Tufts University.

Sanders also reached out to high school students — 17-year-olds are eligible to vote in the Iowa caucuses if they reach 18 by Election Day in November. They are “an electorate that’s never been spoken to,” Kawashima-Ginsberg said in a phone interview.

Sanders’ efforts paid off.

He saw some of his biggest margins in Iowa counties with large universities. He won both Johnson County, home to the University of Iowa, and Story County, home to Iowa State University, with 59.5% of the vote, according to the Associated Press.

It is questionable, however, if this youth-centered strategy will be enough to carry Sanders to the nomination.

While Sanders may have an advantage in Iowa and New Hampshire, where a long ground campaign offers the chance for a sustained mobilization effort, he may be unable to repeat his success in later primaries after the campaign picks up speed.

On the Republican side, there were fewer surprises regarding how age factored into caucus results. Of particular note is that Donald Trump won second place in all age brackets, except young voters.

“Even millennial Republicans are open to social change,” said Redlawsk. “They’re not interested in racial and ethnic attacks.”

Also of note, Rand Paul performed better among young Republican voters than his state average. Younger Republicans tend to lean libertarian and also may have responded well to Sen. Paul’s youth-focused mobilization efforts.