BERLIN – As Germany’s president expressed his sympathy and shock during a candlelight vigil for nine people killed by an immigrant-hating gunman, a woman called out from the crowd, demanding action, not words. But the country’s leaders are struggling to figure out how to counter a recent rise in right-wing hate, 75 years after the Nazis were driven from power. The shooting rampage Wednesday that began at a hookah bar in the Frankfurt suburb of Hanau was Germany’s third deadly far-right attack in a matter of months and came at a time when the Alternative for Germany, or AfD, has become the country’s first political party in decades to establish itself as a significant force on the extreme right. In the wake of the latest spasm of violence, Chancellor Angela Merkel denounced the “poison” of racism and hatred in Germany, and other politicians similarly condemned the shootings. The rampage followed October’s anti-Semitic attack on a synagogue in Halle and the slaying in June of a regional politician who supported Merkel’s welcoming policy toward migrants.