AMES, Ia. — Beto O'Rourke is emphasizing the role young people will play in the 2020 election during his second swing through Iowa, telling a group of mostly college students Wednesday night that they will lead the country on generational issues such as climate change.

"You’re the leaders of this moment and you always have been," he said, noting the young people who stormed the beaches of Normandy and led protests during the civil rights movement.

Leaders of progressive change "have always been distinguished not just by their leadership, but by their youth," O'Rourke said. "Perhaps because they understand better than anyone else that they will bear the consequences of the current policies unless they change them — sometimes by forcing the conscience of this country."

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O'Rourke spoke from the Maintenance Shop in the Memorial Union on Iowa State University's campus. He also has stops planned at Morningside College in Sioux City, Iowa Central Community College in Fort Dodge, the public library in the college town of Grinnell and the University of Iowa in Iowa City.

After he spoke Wednesday night, O'Rourke told reporters that young people are critical to his 2020 efforts, not just because they can provide votes, but because their priorities will help set the country's political agenda.

"Young people — they are where the action, the energy, the votes and the leadership is right now," O'Rourke said. "And so that’s why I’m here at Iowa State."

O'Rourke emphasized climate change in his 20-minute speech and again in his 20-minute question-and-answer session. He said it will take "something just short of a miracle" to tackle what he called an "existential" threat to humanity.

"I don’t know what the odds are of us being able to accomplish it," he said. "But I know that it absolutely has to start now in this room right here in Ames, Iowa."

At 46 years old, O'Rourke is among the younger Democrats running for president in 2020. Two septuagenarians lead many of the early polls: Vermont Sen. Bernie Sanders is 77 years old, and former vice president Joe Biden, who has yet to formally enter the race, is 76.

O'Rourke has emphasized his relative youth on the campaign trail, energetically hopping atop counters and tables to address crowds and competing in a 5-kilometer run during his last trip to Iowa.

Asked whether he considers himself to be one of those young people he referenced in his speech, the former congressman said everything is relative.

"The gentleman who asked the question is young enough to be my son," O'Rourke said. "And in some contexts, 47 years old, which is how old I’ll be in September, is young. I had always thought of it as being old when I was a younger man. So I don’t know. I feel good. I feel young."

O'Rourke announced earlier in the day that he had raised $9.4 million in the first 18 days of his campaign.

Among those candidates who have so far revealed their first-quarter fundraising totals, Sanders leads the pack with $18.2 million. California Rep. Kamala Harris raised $12 million, South Bend, Indiana mayor Pete Buttigieg raised $7 million and California entrepreneur Andrew Yang raised $1.7 million.

"We endeavor to do nothing short of starting the largest grassroots campaign in this country’s history," O'Rourke told reporters. "So this is a good start for us so far."

This is O'Rourke's second trip to Iowa since he announced last month he would run for president. His first trip took him to 18 events across 13 Iowa counties. He's setting a similarly frenetic pace this week, scheduling 15 public events across 10 counties with a focus on college towns and university campuses.