WASHINGTON — On Labor Day, Vice President Kamala Harris plans to campaign in Detroit before heading to Pittsburgh to join President Joe Biden. This strategy aims to showcase their support from labor unions in vital Rust Belt states.

Harris’ appearance with Biden in Pittsburgh next Monday will mark their first joint campaigning effort since she secured the Democratic presidential nomination.

Additionally, Minnesota Gov. Tim Walz, who is Harris’ running mate, will be campaigning in Milwaukee on Labor Day as the campaign actively engages in the three crucial “blue wall” states—Michigan, Pennsylvania, and Wisconsin—that may play a decisive role in the 2024 election.

The Harris campaign has not revealed specific details about the visits but mentioned that they will focus on seven key battleground states, participating in Labor Day parades and engaging with local union members. Other hotly contested swing states include Georgia, Arizona, Nevada, and North Carolina.

Labor Day often signifies the unofficial beginning of the final stretch in a presidential campaign, with millions of voters becoming more engaged in the electoral process. In some states, mail-in ballots will be distributed as early as late September, ahead of the general election on Nov. 5.

Before he exited the race on July 21, Biden was trailing Donald Trump in Pennsylvania, Michigan, and Wisconsin. Currently, Harris holds a slight advantage in Michigan and Wisconsin, based on the Real Clear Politics average of polls, while Pennsylvania remains nearly a tie.

Harris has received endorsements from the United Auto Workers union, which is prominent in Michigan, and the United Steelworkers, which has a significant presence in western Pennsylvania, including Pittsburgh.

However, in his 2016 election win over Hillary Clinton, Trump made considerable gains with union members in Pennsylvania, Wisconsin, and Michigan—even with union leaders endorsing Clinton—and this helped him secure victory in those states.

Biden regained some of these crucial voters in the 2020 election, enabling him to win Pennsylvania, Wisconsin, and Michigan back for the Democrats. Now, Harris aims to replicate those successes.

The Harris campaign still does not have the endorsement of the Teamsters union, which has not yet backed either Harris or Trump. Teamsters President Sean O’Brien recently spoke at the Republican National Convention, making a rare appeal to Republican voters, which has drawn criticism from many Democrats.

On August 15, Biden and Harris appeared together in Largo, Maryland, at an event promoting their administration’s work to reduce prescription drug costs. However, this visit was deemed an official White House event rather than a campaign occasion. Harris also joined Biden on stage to support him after his speech at the Democratic National Convention last week in Chicago, which was largely interpreted as a farewell address.

While Harris positions herself as a candidate looking toward the future, the Trump campaign has been trying to link her to Biden’s unfavorable approval ratings, especially regarding concerns about the economy and inflation.

Contact Joey Garrison on X, formerly known as Twitter, @joeygarrison.