Democrats won voters in union households by 22 percentage points in the 2026 midterm elections, rebuilding their advantage with a longtime constituency, according to the CNBC Voter Poll.
The margin was nearly three times Kamala Harris's eight-point advantage in 2024 and exceeded the party's 16-point lead in 2020. CNBC Television presented the findings in “How Democrats Won Back Union Voters,” published Nov. 12.
About one in six voters belonged to a union or lived with someone who did, the poll found. Democrats' advantage among those households was the largest in eight years.
The gains followed strains in the party's relationship with organized labor. In 2024, the Teamsters declined to endorse a presidential candidate after backing Democrats in six consecutive presidential elections.
The union's own polling showed more participating members favored endorsing Donald Trump than Harris. Some local Teamsters chapters nevertheless backed Harris, and the national union's position did not represent every union.
The United Auto Workers endorsed Harris that year, but its president said candidates could no longer rely on their party label to secure support.
“The days of just blindly giving our endorsements to people because of party affiliation are over,” the union's president said. “They're going to earn our support, and the candidates that do not earn it will not get it.”
In Michigan, United Auto Workers volunteers knocked on 100,000 doors and made 500,000 telephone calls during the 2026 campaign, the union said. It recruited more than 1,000 members to volunteer and targeted competitive congressional districts.
The effort formed part of what the union described as one of its largest political organizing campaigns in recent history.
Harris won Michigan union households by 10 percentage points in 2024, CNBC's polling figures showed. Democrat Abdul El-Sayed won them by 25 points in his Senate race this year, while Jocelyn Benson won them by 27 points in the governor's race.
Those results came from different races. The polling did not establish how much the union's campaigning contributed to the margins or definitively explain what motivated voters.
Nationwide, AFL-CIO volunteers reached nearly 15 million voters since Labor Day through visits, telephone calls and workplace outreach, the federation said. Its data showed 83% of union voters were very motivated to vote, up 10 percentage points from 2022.
Labor's political activity did not amount to uniform support for Democrats. Teamsters President Sean O'Brien said he personally voted for a Republican Senate candidate in Florida this year. The union declined CNBC's request to participate.
The results left open whether Democrats could retain their wider advantage in the 2028 presidential election. The polling did not establish whether the midterm gains would carry into that contest.
