PITTSBURGH — When former President Barack Obama comes to Pittsburgh next Thursday to campaign for Vice President Kamala Harris in the home stretch for next month’s election, he will be returning to a very different western Pennsylvania from the one he won robustly in 2008 and less so in 2012.

In 2008, Obama ran on a message of aspiration, using a slogan of hope and change to create a coalition of working-class white people long part of the New Deal Democrats, minorities, young people, and educated professionals.