Honolulu City Council member Tulsi Gabbard, who hopes to become the first person of the Hindu faith to serve in the U.S. Congress, easily won the Democratic primary for the House of Representatives in Hawaii’s 2nd Congressional District Aug. 11.

She romped to a surprisingly decisive victory over former Honolulu mayor Mufi Hannemann. Polls had shown her with just a slight lead just two weeks before the election ...