Two party-backed millennials won Democratic nominations to Philadelphia City Council on Tuesday night, all but ensuring an injection of youth to Council after a primary season that drew a surge in newcomer candidates.

Isaiah Thomas, 34, and Kathy Gilmore Richardson, 35, were among the top five vote-getters in the Democratic primary for Council, a body where the average age is 58 and no current members are younger than 45.

Incumbent Helen Gym was the top vote-getter late Tuesday, with 106,000 votes. Allan Domb, and Derek Green had received 65,000 and 60,000 votes respectively, all but guaranteeing their reelection in a city where registered Democrats outnumber Republicans by a 7-1 ratio.

With 28 Democrats running — the most in 40 years — standing out was difficult. The crowd was full of would-be firsts: a first-generation immigrant, an openly gay man, a transgender woman. Several activists were vying for the job and campaigning against what they saw as a weakening party machine. The slate as a whole leaned left, making it tough to stand out with progressive policy ideas.

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In the end, the Democratic machine did help lift the victors. All five who won were endorsed by the party, though each also benefited from fundraising, coalitions, union endorsements, and support of independent wards. And though Thomas and Gilmore Richardson are first-time election winners, both have ties to politics.

Gilmore Richardson worked for retiring Councilwoman Blondell Reynolds Brown for 11 years before deciding to run on her own, and with the incumbent’s backing.

Gilmore Richardson, a mother of two young children, campaigned on funding safe schools, public safety, and efficiency in government.

“I’m feeling excited about the possibility of being the youngest African American woman ever elected to City Council at-large,” Gilmore Richardson said late Tuesday from her campaign party in Wynnefield. She noted how many times she was counted out or told, “It’s not your time” or “You’re too young.”

“Well,” she said, "Philadelphians said they want Kathy Gilmore Richardson.”

Thomas previously worked for former City Controller Alan Butkovitz. Now the executive director of Philadelphia Freedom Schools and a head basketball coach at Sankofa Freedom Academy Charter School, he also ran in 2011 and 2015. In this third attempt, he received ward and labor endorsements citywide. Thomas pledged to help fix city school infrastructure and to bolster educational and work training programs for young people.

"I don’t come from a traditional political family,” Thomas said Tuesday night, thanking supporters who have helped him over the last decade. “It’s just a little different when you’re on the outside trying to get in.”

With so many candidates running, getting information and messaging to voters was difficult, and that was on full display Tuesday. One woman voting in Frankford said that she didn’t remember her choices for the at-large seats but that her five picks were all women. Several voters said they were going to vote for one or two specific people, rather than a slate of five. And ballots handed out at the polls, many based on ward endorsements, also swayed voters.

Shraff Rjulah of Francisville pulled out the piece of paper his committee person in the 15th Ward had given him to recall his votes for Gilmore Richardson, Green, Domb, Gym, and Eryn Santamoor. “I lose track of the ins and outs,” said Rjulah, 72. “If they don’t go to jail, they can get my vote.”

Most have attributed the crowded field this year to two incumbents — Reynolds Brown and William Greenlee — choosing not to seek reelection as well as a growing national interest in running for office, particularly from progressive newcomers. Initially more than 40 people announced bids for in their first chance to run for Council since President Donald Trump was elected in 2016.

Gym easily turned out the coalition that helped her first get elected in 2015 — and then some. She had the power of incumbency — a record of legislation standing up for renters and low-wage workers and for affordable housing — and the second-most money of any candidate.

Domb poured more than $1 million into his reelection campaign, airing TV ads months ahead of the election. His support had also grown over his first term from voters who saw him as an independent voice on Council willing to question administration spending and policies. He was the only incumbent not endorsed by Mayor Jim Kenney.

Green won the primary with the toughest climb toward reelection — a bad ballot position and fewer resources than Domb and Gym, but with the help of the party and endorsements.

In the Republican at-large race, incumbent Al Taubenberger, Dan Tinney, Matt Wolfe, Bill Heeney, and incumbent David Oh — at the back of the pack — were the top five vote-getters. All five will be on the ballot in November, vying for two seats reserved for the minority party.

Staff writers Juliana Reyes, Justine McDaniel, and Laura McCrystal contributed to this article.