“It’s time for change,” Democratic congressional candidate Melat Kiros, a political newcomer and self-described democratic socialist, said in her campaign’s TV ad.

On Tuesday night, primary voters in Denver agreed, giving the nomination to the 29-year-old, while at the same time handing 29-year incumbent U.S. Rep. Diana DeGette her walking papers.

Kiros’ commanding win — she was ahead of DeGette by nearly 10 percentage points at 4 p.m. Wednesday, up from the nearly 6-point lead she enjoyed at 10 p.m. on election night, when the Associated Press called the race — marks a generational shift in the deep blue 1st Congressional District, which has been represented by DeGette, 68, since the mid-1990s.

If she wins in November, which is considered a near certainty in the most solidly Democratic seat in the state, Kiros will become only the second member of Congress from Gen Z, joining U.S. Rep. Maxwell Frost, a Florida Democrat.

She also leapfrogged dozens of Denver Democrats who have been biding their time, waiting for DeGette, a late Baby Boomer, to step aside and open up a seat that has only had two congressional representatives since Richard Nixon was president. Prior to DeGette’s 15-term tenure, Democrat Pat Schroeder, who became a national leader on defense and family issues and briefly explored a presidential run, held the seat for 12 terms after winning her first term in 1972.

University of Colorado Regent Wanda James, 62, who represents the same voters as DeGette in the the Denver-based congressional district, became the first experienced politico to mount a primary challenge against the incumbent since the late 1990s, when she launched her candidacy last year, but her campaign didn’t catch fire and she finished with roughly 7% of the vote.

Republican Christy Peterson won the GOP nomination without opposition, though her chances in November are slim. Roughly 10 times as many voters cast ballots in the 1st CD’s Democratic primary as voted in the Republican primary.

Kiros’ upset also points to a leftward movement in the Democratic Party that her allies describe as a return to the party’s roots — prioritizing workers, instead of corporate interests — but that Republican critics and even some Democrats call an alarming lurch from the values shared by most voters.

“Denver voters of all ages, of all races, of all religions sent a clear message: We will not wait,” Kiros told an ebullient crowd at her election night watch party in Denver after she had been declared the winner. “We will not wait to take the fight to Donald Trump and the oligarchy. We will not wait to abolish (U.S. Immigration and Customs Enforcement) and pass ‘Medicare for All.’ We will not wait to put an end to the politics of the past, to get big money out of our politics and to reject corporate PACs and (the American Israel Public Affairs Committee) — and no, we will not wait to end the genocide in Palestine.”

DeGette agrees with Kiros on most of those points and, with her seniority in Congress, is arguably in a better position to accomplish them. She’s a co-sponsor of “Medicare for All” legislation and said at a recent candidate forum that she agrees that ICE should be abolished. As the ranking Democrat on the Committee on Energy and Commerce’s Subcommittee on Health — she was in line to chair the key panel if Democrats take the House majority in November — DeGette could have wielded significant influence in pushing legislation.

The chief policy dividing line between the candidates turned on their respective support for Israel in its war with Hamas. It’s the same fault line that’s split Democrats across the country, including in New York a week before Colorado’s primary, where two incumbent House members lost primaries to Democratic socialists.

Before moving back to the Denver area and launching her campaign, Kiros lost her job as a corporate attorney in New York after refusing to take down an open letter that defended student protesters who were criticizing Israel’s response to attacks by Hamas in 2023.

“I was asked to take it down, said no, and was promptly let go,” she told Colorado Politics, adding that she’d been struck by what she described as similarities between Israel’s assault on Gaza and the genocide in Tigray, Ethiopia, which is where her parents lived when she was born, before immigrating to the United States when she was an infant.

Kiros has called for the U.S. to embargo arms to Israel, including funding for the defensive Iron Dome. DeGette has said she supports continuing funding for defensive systems.

Kiros rode a wave of dissatisfaction with the Democratic Party’s Washington, D.C. class to accomplish something that’s only happened twice in Colorado in the last 50 years — ousting a member of the state’s congressional delegation in a primary. She shares the distinction with Republican U.S. Rep. Lauren Boebert, who defeated five-term U.S. Rep. Scott Tipton in 2020 in the 3rd Congressional District and could be her colleague in six months.

The difference between the two upsets is that DeGette’s team saw it coming, from the incumbent nearly losing her bid for reelection outright at the district assembly in late March, when Kiros won just over 67% of the delegate vote and DeGette got just under 33%, barely clearing the required 30% to make the June 30 primary ballot.

DeGette’s campaign and her backers sprung into action, pouring millions into ads attacking Kiros and boosting the incumbent, but Kiros mobilized what she said on election night was 6,500 volunteers, who knocked 115,000 doors and made 500,000 calls, with a big assist from national supporters organized by the Democratic Socialists of America, Justice Democrats and Working Families Party.

“They said the establishment and the oligarchy is just too big to overcome,” Kiros said in her victory speech. “You are the proof that the power of organized people beats the power of organized money.”

Republican campaign strategists seized on Kiros’ win as proof that the GOP can portray the opposition party as out of step from voters in swing districts, pointing to Colorado’s tossup 8th Congressional District, where state Rep. Manny Rutinel won the Democratic nomination to challenge Republican U.S. Rep. Gabe Evans, who won election two years ago by fewer than 2,500 votes.

“The socialists takeover of the Democrat Party is no longer confined to deep-blue strongholds,” tweeted Mike Marinella, the National Republican Congressional Committee’s national press secretary, linking to a story about Kiros unseating DeGette. “The radicals are taking over the battleground districts, putting must-win seats out of reach for Democrats and sinking their chances of flipping the House.”