Democratic presidential nominee Kamala Harris and Republican nominee Donald Trump are in a tight race for the White House. Every voting bloc will count – including members of labor unions and other people in their households.

The majority of union leaders have over generations endorsed Democratic candidates, and this race is no exception. Although rank-and-file union members have also historically sided with the Democratic Party by large margins, that support has wavered for at least the past 45 years. In 2016, exit polls indicated that voters in union households supported Democratic nominee Hillary Clinton over Trump by only 8 percentage points, down from 18 percentage points in 2012 when Barack Obama was on the ballot.

No Democratic presidential nominee had fared worse with union voters since Ronald Reagan’s wins over Jimmy Carter and Walter Mondale in 1980 and 1984.

Union voters are particularly prominent in Michigan, Pennsylvania and Nevada, three swing states where the share of voters who belong to unions is above the national average of 10%.

A late 2023 New York Times/Siena College poll of six swing states that Joe Biden won in 2020 – those three plus Arizona, Georgia and Wisconsin – shows that Biden and Trump were tied at 47% among union voters when they were asked who they’d vote for in 2024. Biden had an 8 percentage point advantage with these same voters in 2020, according to a different survey.

3 key issues

Union voters, like all U.S. citizens, are concerned about many issues. But they are more likely than most people to seriously consider a candidate’s record in terms of support for workers and organized labor. Labor historians generally concur that the Biden administration has the second-strongest labor-friendly record, after Franklin D. Roosevelt.

And I find that historian Nelson Lichtenstein, who contends that Trump’s years in office were bad for organized labor, is representative of how labor experts see his track record.

In my view as a labor studies scholar, three aspects of the candidates’ records are the most likely to sway union members one way or the other.

Federal workers

Trump signed three executive orders in 2018 that restricted the labor rights of approximately 950,000 federal government employees who belong to unions. In 2020, he signed another measure, known as Schedule F, that The Washington Post described as “designed to gut civil service job protections.”

Biden rescinded those executive orders. He also established a White House task force charged with making recommendations for how to streamline the procedures for federal worker union organizing, which Harris chaired. The number of federal employees in unions has risen by tens of thousands during the Biden administration.

Union elections

Rules governing how elections are conducted once workers express an interest in forming a union date back to the 1930s, when Roosevelt signed the National Labor Relations Act into law. The National Labor Relations Board, created by that legislation, oversees union elections.

In 2019, when Trump appointees held a majority of the NLRB’s five seats, the board overturned an Obama-era NLRB ruling mandating speedy elections. In 2023, when Biden’s appointees were in the majority, the board issued a ruling favorable to unions that rolled back that Trump-era ruling.

Today, when a majority of workers in a workplace say they want union representation, an employer must either recognize and bargain with the union or seek an election. If that employer violates labor law in the period before the election, the election is called off and the NLRB may order the employer to recognize and bargain with the union.

OSHA

The Occupational Safety and Health Administration, a Labor Department agency, is responsible for U.S. workers’ health and safety.

Fewer workplace inspections occurred during the Trump administration than during Obama’s second term. This decline is largely attributable to the slow hiring of new OSHA inspectors to replace those who had retired.

The number of inspections is rising again. However, by OSHA’s calculations, workplace accidents and fatalities have increased during the Biden administration.

The Trump administration issued no workplace rules about coronavirus safety, leaving hundreds of thousands of people employed in health care, groceries, meatpacking and education at risk.

By comparison, two days after taking office in 2021, Biden issued an executive order that established masking guidelines, and his administration made health and safety protocols on the job during the rest of the COVID-19 pandemic a high priority.

Compared with the inaction by the Trump administration during the COVID-19 pandemic, the Biden administration has been more active in proposing health and safety measures. For example, in July 2024 it proposed rules designed to protect some 36 million workers from health risks associated with extreme heat. After a period for written comments, public hearings will be held on the bill.

When Trump tried cutting OSHA funding for 2018 by approximately US$10 million, Congress blocked his efforts. The Biden administration is seeking a 3.7% increase in OSHA’s budget for the 2025 fiscal year.

Legislative and gubernatorial records

Harris was a U.S. senator before she became vice president; her vice presidential running mate, Tim Walz, is the governor of Minnesota and was a member of Congress before that; and Republican vice presidential candidate JD Vance is currently a U.S. senator as well. The candidates’ records in those positions are also indicators of what they might attempt to do in the White House.

The AFL-CIO, the largest umbrella organization for U.S. unions, gave Harris a lifetime score of 98% on her Senate voting record. Walz got a 93% rating for his votes from the AFL-CIO when he served in the House of Representatives. He belonged to the National Education Association, the nation’s largest labor union, while working as a high school teacher.

As Minnesota’s governor, Walz signed into law paid sick days for the state’s workers and a measure that made Minnesota the first state to establish a minimum wage for Uber and Lyft drivers. In 2023, Walz also signed a law that established the Nursing Home Workforce Standards Board to oversee the health and welfare of nursing home workers.

The AFL-CIO has given Vance a 0% rating for his Senate votes as of mid-2024. Among other things, Vance opposed the nominations of several judges and government officials with pro-labor track records.

Addressing auto workers

Perhaps the most visible sign of Biden’s support for labor unions came when he walked a Michigan picket line with striking members of the United Auto Workers in September 2023. He was the first president to do so.

Trump turned up nearby the next day. He gave a speech at a nonunion auto parts plant.

More recently, Trump did himself no favors with labor voters and their allies when, in a highly publicized conversation with Tesla, SpaceX and X CEO Elon Musk, he praised Musk for firing employees who spoke out on workplace problems and attempted to unionize.

How union households will vote in 2024 is not clear. But there’s no doubt that the Harris and Trump campaigns are certain that it will matter, just as it did in 2020, when Biden narrowly won Michigan, Wisconsin and Pennsylvania – and in 2016, when Clinton lost those states.

Robert Forrant does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.