George Hornedo, a liberal activist and Democratic Party strategist in Indianapolis, had already been weighing a primary challenge to the local congressman when he was confronted last month by a senior Indiana Democrat.

Asked whether he was planning a run, Mr. Hornedo, 34, acknowledged he was considering it. The woman, he recalled, told him he was “going to get hurt.” He posted his recounting of the interaction on TikTok, where it quickly went viral. “Don’t let them scare you off,” one commenter wrote.

On Wednesday, Mr. Hornedo announced his campaign against the nine-term incumbent, Representative André Carson, while deriding him and those like him as “do-nothing Democrats” and promising a new generation of leadership for Washington. “The Democratic Party cannot win the future with a leadership structure that is built for the past,” he said in an interview.

A small but growing group of young Democrats are being propelled to act by outrage among rank-and-file voters, and especially among young people. Infuriated by the early months of President Trump’s second term, impatient with the status quo and frustrated with party leadership, they are mounting bids for office.

In California, Jake Rakov, 37, a onetime Capitol Hill aide to Representative Brad Sherman, 70, is challenging his former boss. And even Representative Nancy Pelosi, 85, the California Democrat who stepped down from her two-decade leadership role in 2023, faces a primary challenge, from Saikat Chakrabarti, 39, the former campaign manager for Representative Alexandria Ocasio-Cortez of New York, who ran a similar playbook in her first race for Congress.

Some of these efforts look like long shots against well-funded and better-known incumbents. But they amount to a manifestation of the anger felt by voters toward the Democratic Party — after President Joseph R. Biden Jr., ignoring their concerns, waited until late in the game to abandon his attempt at re-election — and the sentiment that a younger generation might be better equipped to oppose Mr. Trump.

“They’re looking to build a Democratic Party that will fight instead of fold,” said Amanda Litman, the leader of Run for Something, a progressive group that pushes young Democrats to run for office. Young people, Ms. Litman said, were essentially saying: “It’s time to pass the torch. And if they’re not going to pass it, we’re going to take it.”

Here’s a look at three young Democrats who recently announced runs for office.

Seeking to shake up the status quo

A member of the Indiana Democratic Party representing the Latino caucus, Mr. Hornedo (rhymes with tornado) has a résumé that does not quite qualify him as a party outsider. He held a communications role in the Obama administration’s Justice Department and has worked for a range of prominent Democrats, including Pete Buttigieg, the former transportation secretary, who has had presidential ambitions.

But Mr. Hornedo said he rejected any labels like “progressive” or “establishment,” arguing instead that the split in the party is between those like himself who feel a sense of urgency to shake up the status quo and those “who believe that our system and institutions are largely working for people, and we simply have to protect them and manage them in this decline.”

Mr. Hornedo said that he planned to take a more active role than Mr. Carson in building up the Democrats’ bench in Indiana and that he was especially interested in pushing for more affordable housing in Indianapolis, which Mr. Carson has represented since 2008. In a statement, Mr. Carson said he was a lifelong progressive and invited “all voices to join me to defeat far-right extremism.”

Tired of compromise

Kat Abughazaleh, a 26-year-old former researcher for Media Matters, a liberal advocacy organization, first gained online attention for her social media posts and videos skewering conservative media personalities.

Last month, she entered the political arena herself, announcing a primary challenge against Representative Jan Schakowsky, an Illinois Democrat first elected the year Ms. Abughazaleh was born, with an unusual tagline: “What if we didn’t suck?”

Ms. Abughazaleh (pronounced AH-boo-guh-ZAH-lay) said she had grown tired of watching Democrats compromise and work with Mr. Trump, and had been dismayed to see Democratic leaders who had called Mr. Trump a fascist and a threat to democracy show up to his inauguration.

“I was hoping that someone would do something in the chambers or legislatively, or speak out,” she said. “And instead, there were a lot of headlines of, ‘Oh, we want to work with DOGE’ — compromising on basic human rights, rolling over almost immediately,” she added, referring to Elon Musk’s effort to slash the federal government, known as the Department of Government Efficiency. Eventually, she said she realized that “we’re all we’ve got — no one else is coming to save us.”

Ms. Abughazaleh, a progressive who is making the cost of living a major part of her platform, is taking on a fellow progressive in Ms. Schakowsky. But she argues that it is time for Ms. Schakowsky, who is 80, to give way to a new generation.

In a statement, Ms. Schakowsky said that she had not yet decided whether to retire or run for re-election but that she welcomed “new faces getting involved as we stand up against the Trump administration.”

No ‘time to waste’

Deja Foxx’s upbringing would stand out among members of the House. Growing up in Tucson, Ariz., Ms. Foxx was homeless at one point as a teenager, and she worked at a gas station to help make ends meet.

While in high school in 2017, she confronted Senator Jeff Flake of Arizona, a Republican, at a town hall, asking him about his support for a bill that allowed states to direct funding away from Planned Parenthood, an exchange that went viral. Since then, Ms. Foxx has worked on Democratic campaigns, including on former Vice President Kamala Harris’s run last year.

But last November left her disheartened. And Ms. Foxx, 24, was alarmed by the relatively staid reactions from Democrats to Mr. Trump’s joint address to Congress in March, which she attended in person.

“I left balancing both a feeling of disappointment and a sense of urgency,” she said, adding later, “These cannot be the people who are standing between Donald Trump and Elon Musk and your grandmother’s Social Security checks.” She went on, “These cannot be our strongest fighters.”

Ms. Foxx announced a run for an open House seat in southern Arizona this month, joining a crowded special election field vying to replace Representative Raúl Grijalva, who died of complications from lung cancer in March. She said she was representing young people and members of the working class who want to see a fiercer resistance to Mr. Trump.

“For the people who tell me to sit down and wait my turn, I have nothing to say to them other than, ‘We don’t have time to waste,’” she said.