India, Aug. 19 -- Voters in California's 14th Congressional District went to the polls on Tuesday to choose a successor to former Representative Eric Swalwell, in a special election runoff between two Democrats that has evolved into one of the most closely scrutinised tests yet of outside money's influence over the party's internal direction.

State Senator Aisha Wahab, a progressive who entered the race as the clear early favourite, faced Bay Area Rapid Transit board president Melissa Hernandez, a more moderate figure who has drawn heavy financial backing from the American Israel Public Affairs Committee's political arm. Because both finalists are Democrats, the seat was guaranteed to remain in Democratic hands regardless of the outcome,...