Vice President Kamala Harris rallied members of one of the nation’s largest labor unions in a key battleground state on Tuesday, redoubling Democrats’ efforts to cast themselves as the true champions of the working class and Republicans as catering to the wealthy.
“November is going to be about two choices, so let’s be clear about that,” Ms. Harris said in Philadelphia, at a convention for the Service Employees International Union. “Whereas the last administration buried our country in debt to pay for tax cuts for billionaires, we are helping dig families out of debt by telling billionaires to pay their fair share.”
Organized labor is a crucial component of President Biden’s fraying coalition as he seeks re-election against former President Donald J. Trump. Although prominent unions have endorsed Mr. Biden, some rank-and-file union members have drifted toward Mr. Trump, part of a political realignment in which white working-class voters have increasingly supported Republicans.
Across six of the top battleground states, 47 percent of union members said they supported Mr. Trump, compared with 42 percent for Mr. Biden, a recent New York Times/Siena College/Philadelphia Inquirer poll found. Other surveys have shown Mr. Biden ahead with union households, but not by wide margins.
Ms. Harris’s speech served as a reminder of what she and Mr. Biden have accomplished for workers and an attempt to shore up support in an important constituency. She highlighted the administration’s efforts to expand health care access, forgive student debt and raise wages.
“We know when unions are strong, America is strong,” Ms. Harris told the crowd of roughly 3,500 S.E.I.U. members.
But her appearance also exposed deep divisions within the Democratic base over Israel’s war in Gaza. For most of her speech, a group of about three dozen protesters chanted “Free, free Palestine” and “Cease-fire now” in the back of the cavernous convention center.
Biden supporters tried to drown them out by chanting, “Four more years.” Notably, the union’s leadership signed on to a letter to the White House last month demanding that President Biden end military aid to Israel until it lifted restrictions on humanitarian aid to Gaza.
Ms. Harris did not address the protesters. It was not clear if she could see or hear them from the stage.
The S.E.I.U. represents about two million health-care, service and government workers and is a close ally of the Biden administration. S.E.I.U. leaders have said they will spend $200 million to mobilize working-class voters for Mr. Biden and other Democrats this election cycle. Union support is vital to Democrats, who rely on their financial backing and on-the-ground organizing muscle. Mr. Biden’s strength with union workers relative to Hillary Clinton, the Democratic nominee in 2016, helped him secure victory four years ago.
The Biden campaign has tried to counter the more recent dip in union enthusiasm. Last year, Mr. Biden joined striking autoworkers in Michigan, becoming the first sitting president to appear in a picket line. For Mr. Biden, who grabbed a bullhorn to address the crowd, it was an extraordinary embrace of organized labor. He has since received the endorsement of several powerful unions, including the United Automobile Workers and the United Steelworkers.
Ms. Harris’s trip to Philadelphia was a return to familiar territory. She and Mr. Biden visit the city frequently, seeing it as the linchpin to victory in Pennsylvania, a state they most likely need to win to retain the White House.
But Mr. Biden has work to do even in this Democratic stronghold. Black voters in Philadelphia, a key part of the Democratic base here and in other major cities, have shown far fewer signs of excitement about Mr. Biden’s candidacy than they did four years ago.
In her speech, Ms. Harris recognized April Verrett, who was elected on Monday as the first Black president in the S.E.I.U.’s history.
And she assailed Mr. Trump for posting a video on social media that contained a reference to the “Reich,” a term often associated with Adolf Hitler’s Nazi government in Germany.
“This kind of rhetoric is unsurprising coming from the former president and it is appalling,” the vice president said, adding: “Once again, it shows that our freedom and our very democracy are at stake.”
Ruth Igielnik contributed reporting from Washington.
