Former President Donald Trump used his McDonald's visit to cast doubt on a part of Vice President Kamala Harris' life story.Win McNamee/Getty ImagesDonald Trump visited a McDonald's in a key Pennsylvania county on Sunday.Kamala Harris said she once worked at a McDonald's, which is a key part of her biography.Trump has repeatedly claimed, without evidence, that Harris did not work at McDonald's.Former President Donald Trump has long been known for his love of the Golden Arches.After landing at the Philadelphia International Airport on Sunday, Trump and his team traveled to a McDonald's franchise in Feasterville-Trevose, Pennsylvania, where he donned an official employee apron and began handing out orders to customers waiting in the drive-thru lane.