They were, many of them, too young to vote.
But the election of Donald Trump had churned up fears of deportation, of backlash against communities of color, of an administration far different from the one that molded their teenage years.
So on Thursday, thousands of high school students marched out of classrooms, casting ballots by way of protest, flooding streets across Los Angeles County.
Ashly Osorio said she joined to take a stand for her cousins. Her mom. Her aunt. All immigrants from El Salvador for whom she fears the worst under Trump's administration. The student at West Adams Preparatory High School, which announced the walkout over a loudspeaker, said she is also anxious about how she'll be treated as a member of the LGBT community.
Osorio was among the estimated 4,000 students from 16 L.A. Unified high schools who left campus, many of them ending up at the University of Southern California, City Hall and other locations.
"It's been a while. I don't remember the last time we had something like this of this magnitude," said Armando Farias, the deputy chief of Los Angeles School Police.
No acts of violence or student arrests were reported.
About 600 students at Hawkins High School in South Los Angeles headed for the doors about 10:15 a.m., said Jazmin Casas, a community representative for the school, which is predominantly black and Latino.
"We ended up opening the gate because we couldn't hold them back," Casas said.
Buzz about rallies began Wednesday as students made plans via text messages and social media.
At South Gate High, a school volunteer estimated that about half of its 3,000 students left about noon and headed to City Hall.
In downtown Los Angeles, about 500 students left Santee Education Complex, according to Jose Lara, a dean at the school.
Erasmo Camacho, a 16-year-old Santee junior, said that demonstrating during school hours was the most effective way to mobilize a large number of students, and that all of his classmates "were able to support each other" in the effort.
He and hundreds of students from other schools made their way to USC and gathered at the Tommy Trojan statue. At one point the crowd joined together, clasping hands to form a human wall.
L.A. Unified Supt. Michelle King said that students have freedom of speech and are allowed to participate in peaceful demonstrations on campus during non-instructional times, within parameters. "They are not permitted to leave school," King said in a statement.
Los Angeles has seen waves of rallies since Trump declared victory. On Wednesday, the downtown area was a sea of protestors, some burning Trump's head in effigy or spray-painting anti-Trump profanities on buildings.
Initially, authorities hoped to intervene as little as possible, Los Angeles Police Chief Charlie Beck said. But once crowds moved onto the 101 Freeway, Beck said the agency "had to change our posture dramatically" due to safety concerns.
Twenty-eight people were ultimately arrested for impeding traffic, police said.
College protestors took a different approach altogether Thursday, choosing to stage demonstrations on campus.
Several hundred Cal State Dominguez Hills students gathered outside the Student Union building in 90-degree heat, toting a multitude of signs: "Still we rise," "Love not hate," "Unafraid, unapologetic, black and brown."
Senior Estephanie Garcia said she joined the protest out of concern that the new administration will be homophobic.
Garcia, who is gay and often has a ribbon with rainbow colors — a popular symbol for LGBT pride — hanging from her pocket, said someone spat on her while she was on her way to vote.
"I'm worried that I'll be harassed, and people will allow it," said the 21-year-old from Cerritos.
In her hands she held a piece of paper that read, in Spanish: "the people United will never be defeated." But, she added, "there's only so much that can be done."
Times staff writer Kate Mather contributed to this report.
6:10 p.m.: This article has been updated with additional comments from students and a school administrator.
3:40 p.m.: This article was updated with additional information from school authorities.