Okinawa voters on Sunday handed an overwhelming victory to a gubernatorial candidate opposed to U.S. military bases, dealing another blow to plans by the U.S. government and Pentagon to construct a new military facility on the Japanese island.

Takeshi Onaga, who is the former mayor of the Okinawan capital of Naha, was declared winner on Sunday evening with a 100,000 vote lead, in an election in which 360,000 voted. Onaga ran on the pledge to oppose new U.S. military bases on the island, including the controversial Marine Corps Air Station Futenma.

For nearly 20 years, the U.S. has sought to transfer the Okinawa base from the city of Ginowan to the Henoko district of Nago, further to the north. This plan has been met with protests by residents, who oppose the hazards of proximity to the U.S. military presence, including sexual assaults by service members, violence, and the environmental threat to the area’s ecosystems.