President Joe Biden plans to promote his pro-labor record Saturday at his first major political rally since he formalized his reelection campaign, appearing alongside union members to make the case that his economic agenda is boosting the middle class.

His campaign says Biden, who will appear at the Philadelphia Convention Center, will “lay out the core principles of his economic message." The president also intends to talk about how a sweeping climate, tax and health care package he signed into law last year has cut the cost of prescription drugs and lowered insurance premiums. It's part of his administration's focus on his achievements during his first two years in office — the centerpiece argument for a second term.

Several of the nation's most powerful unions — including the AFL-CIO, American Federation of Teachers and the American Federation of State, County and Municipal Employees — officially endorsed Biden's campaign on Friday. The first-of-its-kind joint endorsement among the unions and the backdrop of hundreds of workers are part of a meticulously choreographed effort to show the support of labor behind what Biden himself calls the most pro-union president in history.

“I’m saying that my philosophy about building from the middle out and the bottom up is working," Biden told reporters before a fundraiser in Connecticut on Friday evening.

The Philadelphia event also comes amid some encouraging economic news for Biden, with inflation cooling last month, continuing a steady decline in consumer prices primarily driven by lower gas prices, a smaller rise in grocery costs than in previous months and less expensive furniture, air fares and appliances.

The city and Pennsylvania have long been at the heart of Biden's political efforts. Philadelphia was the site of his campaign headquarters in 2020 and the state was one of a handful that had voted for Donald Trump in 2016 but flipped back to Democrats four years later.

Randi Weingarten, president of the American Federation of Teachers, said some union members supported Trump in the past because “there is a lot of grievance in this country and there is a lot of unhappiness. And what Trump was a master at was being able to exploit fear and exploit grievance.”

She said part of the reason the AFT and other top unions endorsed Biden nearly 18 months before Election Day 2024 was to promote Biden’s economic record against Republican-championed cultural issues.

Biden is "going to feel very, very comfortable when he’s in Philadelphia. He’s going to be among friends,” added Lee Saunders, president of the American Federation of State, County and Municipal Employees. He pushed for a coordinated endorsement of Biden’s reelection campaign from top unions early in the cycle.

Until now, Biden's primary campaign activity has been fundraising. He raised money at a private home in Greenwich, Connecticut, on Friday and soon will hold fundraisers in California, Maryland, Illinois and New York.