A self-described champion of labor unions, Biden addressed union workers Monday in Philadelphia as he sought to explain his economic policies to a public worried about the economy, despite easing inflation and low unemployment levels.

THE 'GREAT' DEVELOPER

"It wasn't that long ago we were losing jobs in this country," Biden said ahead of a parade marking the U.S. Labor Day holiday. "In fact, the guy who held this job before me was just one of two presidents in history who left office with fewer jobs in America than when he got elected."

The 80-year-old president mocked Trump as a "great real estate" developer who "didn't build a damn thing," the New York Post reported.

"Under my predecessor, 'Infrastructure Week' became a punchline," Biden said. "On my watch, infrastructure means a decade."

"When the last guy was here, he looked at the world from Park Avenue," Biden said. "I look at it from Scranton, Pa. I look at it from Claymont, Del. Not a joke."

Biden earlier in the day weighed in on the tensions between the United Auto Workers union and the Detroit Three automakers, telling reporters he thought it was unlikely the UAW would strike when its current contract expires on Sept. 15.

That drew a response from union leadership, after the National Labor Relations board  Friday said it would investigate UAW claims that General Motors and Chrysler parent Stellantis were not bargaining in good faith, claims that the automakers deny.

"I appreciate the President's optimism and I also hope that the Big Three will come to their senses and start bargaining in good faith, but we are ready to do what is necessary come Sept. 15 if they don't," said UAW President Shawn Fain in a statement.

Economic issues are likely to play a critical role in the 2024 presidential race, a likely rematch between Biden, a Democrat, and Republican former President Trump.

VOTERS' ECONOMIC WORRIES

A Reuters/Ipsos poll last month showed that the economy, unemployment and jobs remained Americans' top concern. A full 60% of Americans, including one in three Democrats, said they disapproved of Biden's handling of inflation, according to the poll.

Republicans say that Democratic policies helped spark the rise in prices, making Americans pay more for rent, groceries and gasoline under Biden's watch.

The Federal Reserve has raised rates by 5.25 percentage points since March 2022 and the 30-year mortgage rate now stands above 7%.

Biden played up his record of job creation during his administration and took a dig at Trump, saying Trump's presidency saw jobs shrink in America as businesses looked to China for workers.

The Laborers' International Union Local 57 shirts read "We rebuilt Interstate 95 in 12 days," referring to their work to restore service to a thoroughfare after part of it collapsed in June during a truck crash and fire. Rebuilding crumbling infrastructure has been a part of Biden's pitch to voters, with a $1 trillion infrastructure law pumping money into projects built with union labor.

U.S. job growth picked up in August, but the unemployment rate jumped to 3.8%, from 3.5%, and wage gains moderated, according to last week's Labor Department data - signs the labor market is cooling in response to the central bank's rate hikes.

The Fed's preferred inflation gauge, however, has moved down to 3.3%, from its peak of 7% last summer. Although the decline was a "welcome development," Fed Chair Jerome Powell said late last month, inflation "remains too high" and interest rates may need to move higher.

OVERTIME PROMISE

In an opinion piece published ahead of Labor Day in the Milwaukee Journal-Sentinel, Biden highlighted his administration's proposal to extend overtime pay to some 3.6 million Americans and praised unions for being good for the economy.

Pennsylvania is one of a handful of states that are seen as politically competitive and likely to determine who wins the White House in 2024, with the other most competitive states being Arizona, Georgia and Wisconsin.

• Biden on UAW: 'I'm Not Worried About a Strike'