Prime Minister Junichiro Koizumi's sky-high popularity is a thing of the past. Over the last six months, his public approval ratings have declined sharply, as has his image as a charismatic reformer.

But no other figure in the Liberal Democratic Party, which he heads, has emerged to challenge his reign and the only person with the popular clout to succeed him, according to opinion polls, is controversial Tokyo Gov. Shintaro Ishihara. And Ishihara has yet to make a challenge.

Koizumi's two-year term as LDP president runs through September 2003, but the party could seek to find a successor sooner, as has happened in the past.