Kamala Harris turned 60 on Sunday in the final stretch of a knife-edge US election, making campaign stops at Black churches in Georgia as her 78-year-old opponent Donald Trump served fries at a Pennsylvania McDonald’s in a bid to earn working-class credibility. Throughout the day Harris lambasted Trump’s increasingly disparaging, dark language on the trail, saying in an interview on MSNBC that Americans “deserve so much better.” “Donald Trump should never again stand behind the seal of the president of the United States. He has not earned the right,” Harris said. Recently Trump has likened und…