The results of three elections earlier this week could be a bad omen for Prime Minister Junichiro Koizumi and his Liberal Democratic Party. Ms. Kazumi Ota of the opposition Democratic Party of Japan defeated a candidate fielded by the LDP and supported by its coalition partner Komeito in a Lower House by-election in the No. 7 Constituency in Chiba Prefecture. Residents in Iwakuni, Yamaguchi Prefecture and Okinawa, Okinawa Prefecture, elected mayors who oppose the U.S. military base relocation plan pushed by the Japanese and U.S. governments.

In the Chiba by-election, Ms. Ota, 26, won by just 955 votes but her victory is significant because it shows that the DPJ has put its recent e-mail fiasco behind it. The election was the last Diet election for Mr. Koizumi and the first major challenge for Mr. Ichiro Ozawa, who was elected president of the DPJ this month to serve out the term of former leader Mr. Seiji Maehara.

In his campaign speeches, Mr. Ozawa assailed Mr. Koizumi's politics -- a turnabout from Mr. Maehara's style. The new DPJ leader focused on social disparities and social welfare issues and stressed the importance of social safety nets. DPJ members meanwhile visited business firms and associations that had been regarded as supporters of the LDP to consolidate votes -- an election tactic not skillfully employed in the past.