The Democratic Party's regular convention held last Sunday — the first since Renho took over as its chief in September — highlighted the difficulties confronting the No. 1 opposition party as it struggles to win back popular support lost since its crushing fall from power in 2012. Renho's attempt and failure to flesh out the party's policy on phasing out nuclear energy exposed differences among its members and with its organized supporters. She has yet to clarify what the party intends to do in campaign cooperation with other forces — which is viewed as vital for the opposition camp to face up to Prime Minister Shinzo Abe's dominant ruling coalition.

As it is, the DP is far from its eventual goal of resurrecting itself as a contender for governing power. Unless it can develop concrete policy programs that clearly pit itself against the Abe administration and win the hears and minds of voters, the party will hardly be able to pose a meaningful threat to the ruling coalition.

Renho was elected DP chief in September to succeed Katsuya Okada mainly on the strength of her popularity as lawmaker. The more than 1 million votes she collected in her Tokyo constituency in the last two Upper House elections had given hope to DP members that she would help the party regain votes in the Tokyo Metropolitan Assembly election this summer and in the next Lower House election. But things are not developing as they had hoped. The party continues to trail far behind Abe's Liberal Democratic Party in terms of popular support in media opinion polls.