Some of the nation’s top union leaders spoke out in favor of Vice President Kamala Harris’ candidacy and painted former President Donald Trump and his running mate, Ohio Sen. JD Vance, as faux champions of the working class on Thursday.

Speaking on a press call organized by the Democratic National Committee, Service Employees International Union president April Verrett, who leads a union of around two million members, said Harris “understands the struggles that working families face” in contrast to “the harm Donald Trump will do to working people if he gets his hands back on the reins of power.”

Stuart Appelbaum — the president of the Retail, Wholesale and Department Store Union — rattled off Trump’s business history and argued he brought those same tactics “to the White House, hurting workers all across America” during his first term.

“As president during his term, the only winners coming out of the Trump administration were mega corporations and the ultra-rich. The Trump administration stacked the National Labor Relations Board to squash workers’ attempts to unionize and appointed anti-union officials throughout the Department of Labor,” Appelbaum said. “As we saw on the [Republican National Convention] stage last week, he tries and fails to play man of the people when the cameras are on. Donald Trump wants to convey that he is for workers across the country, but he proves time and time again he is all for show.”

The call came on the same day Harris was in Houston to rally with members of the American Federation of Teachers and describe Trump’s economic agenda as bringing “our nation back to failed trickle-down economic policies, back to union busting, back to tax breaks for billionaires.”

“America has tried these failed economic policies before, but we are not going back. No. We will move forward,” Harris said, also declaring that “unions helped build America’s middle class. And when unions are strong, America is strong.”

On the DNC call, Verrett echoed Harris’ remarks, saying “working people together, we're moving forward. We are not going backward,” and praising Harris for standing up “for so many of us who have been left behind: Black, brown, immigrant women, those of us who have been written out of our existing nation's racist and sexist labor laws.” She pledged her union members, among the more active supporters of Democratic candidates and causes, were working to organize and mobilize six million working class voters in key battleground states.

A union leader in one of those key states that will determine the results of November’s election, Michigan AFL-CIO president Ron Bieber, expressed confidence Harris will carry his state in the fall.

“I've never seen energy like this, this time in an election cycle. The workers in Michigan are not going backwards,” Bieber said on the DNC call. “I'm the president of Michigan AFL-CIO now, but I came up through the United Auto Workers. Trump was devastating to the auto industry and auto workers here in Michigan, they are not going to go backwards.”

The UAW endorsed President Joe Biden earlier this year, but has yet to endorse Harris. Union president Shawn Fain, who successfully recruited Biden to become first sitting U.S. president to join striking workers on a picket line last September, told teachers in Houston a day before Harris spoke at the same conference that “everything is at stake” in November and bashed Trump. But he said previously that the union would discuss endorsing Harris internally and didn’t plan “to rush in and just throw it out there.”

But organized labor largely has come out strong for Harris since Biden dropped out on Sunday and endorsed her. 

Beyond SEIU, RWDSU and the AFL-CIO, the 700,000-member Communications Workers of America, the 838,000-member International Brotherhood of Electrical Workers and the 1.8 million-member American Federation of Teachers have all gotten behind the vice president. 

“My friends, my siblings, do you understand our assignment? Are we going full throttle through Nov. 5? Are we going to shatter every record for voter turnout? And are we going to elect Kamala Harris as the next president of the United States?” AFT President Randi Weingarten asked the crowd of teachers in Houston on Thursday before Harris spoke. 

Union politics is already playing a role in Harris’ selection of her running mate, with one contender — Arizona Sen. Mark Kelly — quickly expressing support for the PRO Act amid discussions of his potential candidacy after previously not offering his public endorsement. The legislation, backed by most Senate Democrats and passed by a Democrat-controlled House in 2021, would make unionizing and joining unions easier for workers and is a key priority of labor in the U.S.

Bieber, the Michigan AFL-CIO president, also tore into the record of Kelly’s would-be rival, Vance, on the Thursday press call. Vance, a former venture capitalist who rose to prominence writing a memoir of his path from working class roots in Ohio and Kentucky to the halls of Yale Law, has attempted to frame himself as an avatar of the American worker, mostly through calls to increase domestic manufacturing and decrease reliance on foreign trade. 

“JD Vance has made a career out of touting his so-called populist credentials. He made his fortune selling books that told the story of his blue collar roots, and has pinned himself as a new, worker-friendly generation of Republican,” Bieber said. “This image, like Donald Trump's working man's shtick, is all just a lie.”

Bieber noted that Vance, through 18 months in the Senate, has received a 0% on his legislative scorecard from the AFL-CIO, opposed the PRO Act and introduced legislation with Florida Sen. Marco Rubio that would allow the establishment of “employee involvement organizations,” or employer-backed alternatives to workers unions known as “company unions.”

“In his short tenure as an elected official, Vance has given us all the proof we need that he stands on the side of corporate bosses, not working families,” Bieber said. “Vance can talk all he wants about supporting workers, but when it has actually come time to act, he's put the C-suite crowd first every time.”

At least one major union appears to be entertaining a possible endorsement of Trump and Vance, with Teamsters president Sean O’Brien delivering a speech at the RNC in Milwaukee last week. O’Brien previously met with Trump at his Mar-a-Lago estate and again in Washington earlier this year, but he has also praised Biden as “the most pro-labor president we’ve ever had.” His RNC speech sparked pushback from within his own ranks, with one top Teamsters official announcing he would challenge O’Brien for his leadership role in 2026. 

"The American people aren't stupid, they know the system is broken. We all know how Washington is run — working people have no chance of winning this fight. That's why I'm here today. Because I refuse to keep doing the same things my predecessors did," said O’Brien at the RNC. "Today, the Teamsters are here to say we are not beholden to anyone or any party."

On Thursday, RWDSU’s Appelbaum described O’Brien’s overtures to Republicans as “laughable.”

“The idea that Donald Trump or his MAGA Republican Party is pro-worker in any way, is really laughable and contradicts everything we have seen about Donald Trump during his term in office and since,” Appelbaum said. “He is not pro-worker in any sense of the word, regardless of anyone appearing at his convention.”

“People cannot be confused by the theatrics,” he added. 

Spectrum News’ Susan Carpenter contributed to this report.

NOTE: This has been updated to correct the spelling of Stuart Appelbaum’s name.