Biden joins Kamala Harris at Pittsburgh Labor Day rally: endorsement of unions and an accent change that went viral on social media

Kamala Harris and Joe Biden again campaigned together on Labor Day. As part of a tour of the battleground states, the Democratic candidate stopped by Detroit (Michigan) and Pittsburgh (Pennsylvania), where she was also joined by still-President Biden. However, the thing most talked about was not the content of the speech, but a peculiar change in Harris' accent in just a matter of hours.

After holding a meeting with a negotiating team to discuss possible solutions to the Hamas hostage-taking, Harris and Biden headed straight for the Midwest, where they resumed joint campaign events.

In Pennsylvania, Harris appeared alongside union leaders and opposed the sale of U.S. Steel, the world's 15th largest steel producer. "U.S. Steel is a historic American company. U.S. Steel should remain American owned and operated," said the vice president, who later focused on attacking Donald Trump.

U.S. Steel should remain American-owned and American-operated.

It is vital for our nation to maintain strong American steel companies.

I will always have the back of America's steelworkers.

"While we struggle to move forward, Donald Trump is trying to take us backwards, even to a time when workers had no freedom to organize. (...) We know this will be a close race to the finish. So let's not pay too much attention to those polls, because, as unions and workers know well, we know what it's like to be the underdog," she added.

As for Biden, who has proclaimed himself to be the most pro-union president, he said he trusts Harris to continue his legacy.

Harris' viral accent change

Harris gave the same speech in Pittsburgh and Detroit, which helped social media users identify her marked accent change in the latter city, where she appeared in front of an audience with a larger number of African-American voters.

"Everywhere I go, I tell people: look, you may not be a union member, you better thank a union member for the five-day work week, you better thank a union member for the sick leave, you better thank a union member for the paid leave, you better thank a union member for the vacation time," was the line in which she chose to markedly change her accent.

WATCH: Kamala Harris delivers the same exact line in a speech earlier today in Detroit and again in Pittsburgh a few hours later.

Let’s see if you can spot the difference… pic.twitter.com/FCRqCBqcBZ

This did not go unnoticed by the Trump campaign, who rushed to show a comparison of the speeches on their social media accounts. "Let's see if you can tell the difference...", they posted ironically.