The new leader also needs to change the party's high-handed reputation, worsened by the outgoing Prime Minister Yoshihide Suga who angered the public over his handling of the coronavirus pandemic and insistence on holding the Olympics in Tokyo this past summer.
The long-ruling conservative Liberal Democratic Party desperately needs to quickly turn around plunging public support ahead of lower house elections coming within two months, observers say.
Taro Kono, the vaccinations minister, and former Foreign Minister Fumio Kishida are considered the top contenders, though unusually, two women are competing — ultra-conservative Sanae Takaichi and liberal-leaning Seiko Noda.
Takaichi has risen to a competitive third option after getting the crucial backing of Suga’s predecessor, former Prime Minister Shinzo Abe, whose conservative vision and revisionist stance she supports.
Kono, known as something of a maverick and a reformist, supports eventually phasing out nuclear energy, while Kishida calls for growth and distribution under his “new capitalism,” saying Abe’s economic policy only benefited big companies. Takaichi, by far the most hawkish who wants greater military capability and spending, promises to visit the controversial Yasukuni Shrine. Noda pushes for women's rights and diversity.
Overall, little change is expected in key diplomatic and security policies under the new leader, said Yu Uchiyama, a political science professor at the University of Tokyo.
Analysts think Suga lost support because of party complacency and an increasingly high-handed approach forged during Abe’s long leadership.
Wednesday’s vote is seen as a test of whether the party can move out of Abe’s shadow. His influence in government and party affairs has largely muzzled diverse views and shifted the party to the right, experts say.
The party vote could also end an era of unusual political stability and return Japan to “revolving door” leadership.
“Concern is not about individuals but stability of Japanese politics," Michael Green, senior vice president for Asia at the Center for Strategic and International Studies, told a telephone briefing Tuesday. “It's about whether or not we are entering a period in Japanese politics of instability and short-term prime ministership,” he said. “It makes it very hard to move forward on agenda."
Kono is favored by the public but lacks solid backing of the party's conservative heavyweights, which may set him up for a short-term premiership, while Kishida is seen as a choice who could lead government longer.
Suga is leaving only a year after taking office as a pinch hitter for Abe, who suddenly resigned over health problems, ending his nearly eight-year leadership, the longest in Japan’s constitutional history.