Andrew Yang is leading. Scott Stringer is under a cloud. Their rivals are jostling. View in browser | nytimes.com Continue reading the main story April 30, 2021 By Giovanni Russonello Andrew Yang during a campaign stop in the Bronx. Gabriela Bhaskar for The New York Times With less than two months to go until the all-important Democratic primary, the New York City mayor's race is one of the costliest and most closely watched political campaigns in the country this year. It's also one of the most uncertain. The businessman Andrew Yang is widely seen as the front-runner, mostly thanks to the celebrity profile that he accrued on the presidential campaign trail last year, when he mounted a quixotic run. But with a ranked-choice voting system in place for the first time, and most voters still relatively unengaged and unaware of the candidates involved, no one has emerged with a clear path to victory. "Yang is the front-runner, but a vulnerable front-runner," Doug Schoe...