OSAKA — At an October reception in central Nagoya for delegates to the U.N. COP10 meeting on biodiversity, Mayor Takashi Kawamura seemed to be thoroughly enjoying himself. As he was leaving, his face flushed red, he suddenly broke into English, singing the gospel classic "We Shall Overcome" but giving it his own twist.

"We shall overcome the Nagoya city assembly," Kawamura said, as nervous aides led him to a waiting car.

On Sunday, Kawamura did just that. With his re-election, approval of a referendum to dissolve the city assembly that he backed, and a victory in the gubernatorial election by his ally, Hideaki Omura, Kawamura scored a political hat trick, sending shock waves through the Democratic Party of Japan, whose candidates were drubbed, and increasing pressure on Prime Minister Naoto Kan, the DPJ chief, to dissolve the Lower House.