Biden tends to his base in a painfully close Pennsylvania race against Trump

President Biden jetted across the must-win battleground of Pennsylvania this week to shore up support and take on one of his top liabilities: the economy.

He pitches himself as a native son of Pennsylvania who understands the struggles of working-class voters, especially economically disadvantaged Black voters. Although employment numbers are good, Mr. Biden is saddled with stubborn inflation, high interest rates and high energy and food prices.

Democrats in Pennsylvania, the most populous swing state, are receptive to Mr. Biden’s pitch that billionaires and corporations have taken advantage of working-class people for...