Obama has been on the defensive for saying economically frustrated people in small towns get bitter and "cling to guns or religion" to explain their feelings. Obama later said he regretted offending anyone.
Clinton and other Democrats have expressed concern that Obama's comments make the party look out of touch.
Clinton was campaigning in Scranton to emphasize her middle-class roots. While there, she also planned to visit the grave of her father, Hugh Rodham.