When the Board of Aldermen begins its next session in January, the balance of power will have barely shifted from its current political state, leaving much of the decision-making in the hands of union-backed legislators.

Tuesday’s Democratic primary showed that 2011, when union-backed candidates swept into power, was no fluke. The city’s unions exerted their strength on Tuesday, capturing a decisive victory in the mayoral primary while maintaining their majority on the Board of Aldermen. The results pave the way for an even greater presence of organized labor in the city’s policy-making. At the same time, the hopes of candidates running to dent the union “supermajority” are dimmer after Tuesday’s vote count, when New Haven voters expressed satisfaction with the present dynamics of the board.

“We’re going to work in collaboration,” Ward 22 Alderman Jeanette Morrison said of the Board’s relationship with the mayor. “It’s no more us versus them because Toni Harp buys into the board’s agenda.”

In 20 of the 30 wards, the aldermanic races were uncontested. In 18 of those wards, the incumbent alderman ran unopposed, while in Wards 10 and 13 Anna Festa and Rosa Santana ran without challengers. Of the 10 contested races, seven included incumbents, all of whom emerged victorious after election officials announced the results Tuesday evening.

Currently, union-backed aldermen hold 20 seats on the board. Although affiliations between candidates and unions do not always come in the form of formal endorsements, Tuesday’s results suggest that number is likely to remain materially the same.

And after labor-friendly mayoral candidate Toni Harp ARC ’78 took the Democratic nomination with a wide margin of victory, the dynamic between the Board of Aldermen and the mayor’s office is likely to change come January. Current Mayor John DeStefano Jr.’s relationships with the board and the city’s unions were often contentious throughout his 20-year occupancy of the top seat in City Hall, and the mayor was frequently criticized for stepping over the Board.

Ward 1 Alderman Sarah Eidelson ’12, who endorsed Harp and canvassed with the eventual primary winner, said that she expected the next mayor to regard the board as a set of partners. Harp served on the Board of Aldermen before joining the Connecticut state legislature in Hartford, which several Harp supporters and aldermanic candidates said would facilitate a productive dynamic between the city’s executive and legislative bodies.

The new relationship, Eidelson emphasized, would allow the board to move forward on the three issues that have come to dominate its agenda over the past two years: jobs, youth issues and public safety.

Although some have criticized the unions’ dominance of the board, Eidelson said that the dynamic that emerged after the 2011 election allowed significant progress to be made. She pointed to previous iterations of the board, which had few legislative accomplishments, as contrasts to the current state. Prior to 2011, when union-backed candidates unseated most of them, allies of DeStefano controlled much of the board, allowing the mayor to set the agenda in City Hall.

The force that aimed to shift control of the board away from the union “supermajority,” Take Back New Haven, was largely unsuccessful. Of the four candidates the group fielded, only one, Ward 7 incumbent and Take Back New Haven founder Doug Hausladen ’04, emerged victorious. Hausladen faced Ella Wood ’15, who, while not officially endorsed by UNITE HERE, maintains significant ties to the union.

“I’m a political neophyte,” a visibly exhausted Hausladen said Tuesday evening. “Politics isn’t rocket science but it’s a lot of shoe leather.”

After running unopposed in 2011, Hausladen’s challenge from Wood came as a late-summer surprise. Although Wood says her candidacy came out of a desire to provide better representation for residents of the ward, several observers have suggested that she was encouraged to run by the unions after Hausladen sought to challenge their dominance on the board.

The group’s three other candidates — Greg Smith in Ward 2, Peter Webster in Ward 8 and Patty DePalma in Ward 11 — lost by nearly 40 points on average. All three had sought to bring diversity of thought, which they claim the unions’ dominating presence discourages, to the Board.

Despite his loss, though, Webster remained upbeat Thursday night, saying that he had succeeded by bringing residents of his ward into the democratic process. He emphasized that he will continue to serve his community by keeping the Board’s activities in focus.

“I intend to sting the butts of the people who were elected,” Webster said of his future plans. “They are going into an aldermanic council where everyone votes the party line and nothing gets done.”

Already resigned to losing by the early evening, Smith expressed a similar sentiment to Webster, saying that he planned to run again. Although he remained uncertain as to whether he would run in the general election as an independent, he said that he would attempt to run again in the next cycle.

Smith’s opponent, incumbent Frank Douglass, enjoyed significant support from organized labor, whose resources allowed him to drive voters to the polls far more effectively than Smith. On Tuesday, union members, including Douglass’ wife Connie, drove Yale students and city residents in Ward 2 to the polling place on Edgewood Avenue as Smith stood by watching.

Other candidates not part of Take Back New Haven but also running against union-backed candidates experienced similar defeats. Cordelia Thorpe, who challenged Morrison in Ward 22, received nearly 40 percent less of the vote than Morrison.

Elm City residents cast a total of 5,185 votes in the city’s 10 contested aldermanic races.

MATTHEW LLOYD-THOMAS