Biden is expected to use the backdrop of several small businesses in the onetime steel and manufacturing haven of the Lehigh Valley to make the case that middle-class entrepreneurs and workers are thriving, inflation is waning and that the 81-year-old Democrat deserves a second term in office.

Heavy manufacturing in the so-called Rust Belt began to ebb in the 1970s, hollowing out once thriving American cities as rising costs and global trade drove business elsewhere. Today, Allentown's unemployment stands at around 3.9%, near 20-year lows.

Biden is pairing a bread-and-butter argument about falling consumer inflation and low unemployment aimed at the plurality of voters who say that the economy is their top concern, with the case that Republican Donald Trump's authoritarian tendencies are a threat to U.S. democracy. The latter 2024 election pitch was the subject of his most recent trip to Pennsylvania, which was just last Friday.

Biden has struggled so far to make either message stick with voters. Polls show Biden in a very close race with Trump as many Americans appear to be unenthusiastic about their choices.

Biden aides see Pennsylvania, home to Biden's Scranton birthplace, as a must-win state. He won in 2020 with 50.01% of the vote. In 2016, Trump won Pennsylvania with 48.58% of the vote.

Biden's political aides are in general-election mode, hoping to woo swing-state voters even as Trump's focus remains on the ongoing primary contest in Iowa, which is holding a Republican caucus on Monday but is not expected to be very closely contested in the November election.

Trump, president from 2017 to 2020 and leading the field for the Republican nomination, has made inflation under the Biden administration a key part of his pitch for re-election.

(Reporting by Trevor Hunnicutt; Editing by Kim Coghill)

By Trevor Hunnicutt